neato(1)


NAME

   dot - filter for drawing directed graphs
   neato - filter for drawing undirected graphs
   twopi - filter for radial layouts of graphs
   circo - filter for circular layout of graphs
   fdp - filter for drawing undirected graphs
   sfdp - filter for drawing large undirected graphs
   patchwork - filter for tree maps

SYNOPSIS

   dot [options] [files]
   neato [options] [files]
   twopi [options] [files]
   circle [options] [files]
   fdp [options] [files]
   sfdp [options] [files]
   patchwork [options] [files]

DESCRIPTION

   These  are  a  collection  of  programs  for  drawing graphs.  There is
   actually  only  one  main  program;  the  specific  layout   algorithms
   implemented  as  plugins.  Thus,  they  largely  share  all of the same
   command-line options.  dot draws directed graphs.   It  works  well  on
   DAGs and other graphs that can be drawn as hierarchies.

   neato  draws  undirected graphs using ``spring'' models (see Kamada and
   Kawai, Information Processing Letters 31:1, April 1989).

   twopi draws graphs using a radial layout (see G.  Wills,  Symposium  on
   Graph  Drawing  GD'97, September, 1997).  Basically, one node is chosen
   as the center and put at the origin.  The remaining nodes are placed on
   a  sequence  of  concentric  circles  centered about the origin, each a
   fixed radial distance from the previous circle.  All nodes  distance  1
   from  the  center  are placed on the first circle; all nodes distance 1
   from a node on the first circle are placed on the second circle; and so
   forth.

   circo  draws graphs using a circular layout (see Six and Tollis, GD '99
   and ALENEX '99, and Kaufmann and Wiese, GD '02.)  The  tool  identifies
   biconnected  components  and  draws  the  nodes  of  the component on a
   circle. The block‐cutpoint tree is then  laid  out  using  a  recursive
   radial  algorithm.  Edge  crossings  within  a  circle are minimized by
   placing as many edges  on  the  circle's  perimeter  as  possible.   In
   particular,  if the component is outerplanar, the component will have a
   planar layout.

   If a node belongs to multiple non‐trivial biconnected  components,  the
   layout puts the node in one of them. By default, this is the first non‐
   trivial component found in the search from the root component.

   fdp draws undirected graphs using a ``spring'' model. It  relies  on  a
   force‐directed  approach in the spirit of Fruchterman and Reingold (cf.
   Software‐Practice & Experience 21(11), 1991, pp. 1129‐1164).

   sfdp also draws undirected graphs using the ``spring'' model  described
   above,  but  it uses a multi-scale approach to produce layouts of large
   graphs in a reasonably short time.

   patchwork draws the graph as a squarified treemap (see M. Bruls et al.,
   "Squarified  treemaps", Proc. Joint Eurographics and IEEE TCVG Symp. on
   Visualization, 2000, pp. 33-42). The clusters of the graph are used  to
   specify the tree.

OUTPUT FORMATS

   Graphviz  uses an extensible plugin mechanism for its output renderers,
   so to see what output formats your installation of dot supports you can
   use  ``dot  -Txxx''  (where  xxx  is  an unlikely format) and check the
   warning  message.   Also,  The  plugin  mechanism   supports   multiple
   implementations  of  the  output  formats.   To  see  what variants are
   available, use, for example: ``dot -Tpng:'' and to force  a  particular
   variant, use, for example: ``dot -Tpng:gd''

   Traditionally, Graphviz supports the following:
   -Tps (PostScript),
   -Tsvg -Tsvgz (Structured Vector Graphics),
   -Tfig (XFIG graphics),
   -Tpng -Tgif (bitmap graphics),
   -Timap (imagemap files for httpd servers for each node or edge that has
   a non‐null "href" attribute.),
   -Tcmapx (client‐side imagemap for use in html and xhtml).
   Additional less common or more special‐purpose output  formats  can  be
   found at //http://www.graphviz.org/content/output-formats.

   Alternative  plugins providing support for a given output format can be
   found from the error message resulting from  appending  a  ':'  to  the
   format. e.g. -Tpng: The first plugin listed is always the default.

   The  -P  switch  can  be used to produce a graph of all output variants
   supported by plugins in the local installation of graphviz.

GRAPH FILE LANGUAGE

   Here is a synopsis of the  graph  file  language,  normally  using  the
   extension .gv, for graphs:

   [strict] (graph|digraph) name { statementlist }
   is the top‐level graph. If the graph is strict, then multiple edges are
   not allowed between the same pairs of  nodes.   If  it  is  a  directed
   graph,  indicated by digraph, then the edgeop must be "->". If it is an
   undirected graph then the edgeop must be "--".

   Statements may be:

   name=val;
   node [name=val];
   edge [name=val];
   Set default graph, node, or edge attribute name to val.  Any  subgraph,
   node, or edge appearing after this inherits the new default attributes.

   n0 [name0=val0,name1=val1,...];
   Creates  node n0 (if it does not already exist) and sets its attributes
   according to the optional list.

   n0 edgeop n1 edgeop ... edgeop nn [name0=val0,name1=val1,...];
   Creates edges between nodes n0, n1, ..., nn and sets  their  attributes
   according to the optional list.  Creates nodes as necessary.

   [subgraph name] { statementlist }
   Creates  a  subgraph.  Subgraphs may be used in place of n0, ..., nn in
   the above statements to create edges.  [subgraph name] is optional;  if
   missing, the subgraph is assigned an internal name.

   Comments may be /*C‐like*/ or //C++‐like.

   Attribute  names  and  values  are  ordinary  (C‐style)  strings.   The
   following sections describe attributes that control graph layout.

   A  more  complete  description  of  the  language  can  be   found   at
   http://www.graphviz.org/content/dot-language.

GRAPH, NODE AND EDGE ATTRIBUTES

   Graphviz uses the name=value attributes, attached to graphs, subgraphs,
   nodes and edges, to tailor the layout and rendering. We list  the  more
   prominent   attributes   below.  The  complete  list  is  available  at
   http://www.graphviz.org/content/attrs.

  Graph Attributes
   size="x,y" specifies the maximum bounding box of drawing in inches.

   ratio=f sets the aspect ratio to  f  which  may  be  a  floating  point
   number, or one of the keywords fill, compress, or auto.

   layout=engine  indicates  the  preferred layout engine ("dot", "neato",
   fdp" etc) overriding the default from the basename of  the  command  or
   the -K commandline option.

   margin=f sets the page margin (included in the page size).

   nodesep=f sets the minimum separation between nodes.

   ranksep=f sets the minimum separation between ranks.

   ordering=out  constrains  order of out‐edges in a subgraph according to
   their file sequence.

   rankdir=LR|RL|BT requests a left‐to‐right, right‐to‐left, or bottom‐to‐
   top, drawing.

   rank=same  (or min or max) in a subgraph constrains the rank assignment
   of its nodes.   If a subgraph's name has the prefix cluster, its  nodes
   are  drawn  in  a  distinct  rectangle  of the layout.  Clusters may be
   nested.

   rotate=90  sets  landscape   mode.    (orientation=land   is   backward
   compatible but obsolete.)

   center=n a non‐zero value centers the drawing on the page.

   color=colorvalue sets foreground color (bgcolor for background).

   href="url"  the  default  url for image map files; in PostScript files,
   the base URL for all relative URLs, as recognized by Acrobat  Distiller
   3.0 and up.

   URL="url" ("URL" is a synonym for "href".)

   stylesheet="file.css" includes a reference to a stylesheet in -Tsvg and
   -Tsvgz outputs.  Ignored by other formats.

   splines If set to  true,  edges  are  drawn  as  splines.   If  set  to
   polyline,  edges  are  drawn  as polylines.  If set to ortho, edges are
   drawn as orthogonal polylines.  In all of these cases,  the  nodes  may
   not overlap.  If splines=false or splines=line, edges are drawn as line
   segments.  The default is  true  for  dot,  and  false  for  all  other
   layouts.

   (neatospecific attributes)
   start=val.   Requests  random  initial  placement  and seeds the random
   number generator.  If val is not an integer, the process ID or  current
   time is used as the seed.

   epsilon=n.  Sets the cutoff for the solver.  The default is 0.1.

   (twopispecific attributes)
   root=ctr.  This  specifies  the  node  to  be used as the center of the
   layout. If not specified, twopi will randomly pick  one  of  the  nodes
   that  are  furthest  from  a  leaf node, where a leaf node is a node of
   degree 1. If no leaf nodes exists,  an  arbitrary  node  is  picked  as
   center.

   ranksep=val.  Specifies  the  radial  distance  in  inches  between the
   sequence of rings. The default is 0.75.

   overlap=mode. This specifies what twopi should do if any nodes overlap.
   If  mode  is  "false",  the program uses Voronoi diagrams to adjust the
   nodes to  eliminate  overlaps.  If  mode  is  "scale",  the  layout  is
   uniformly  scaled  up,  preserving  node  sizes,  until nodes no longer
   overlap.  The  latter  technique  removes  overlaps  while   preserving
   symmetry   and  structure,  while  the  former  removes  overlaps  more
   compactly but destroys symmetries.  If mode is "true" (the default), no
   repositioning is done.

   (circospecific attributes)
   root=nodename.  Specifies  the  name  of  a  node occurring in the root
   block. If the graph is disconnected, the root  node  attribute  can  be
   used to specify additional root blocks.

   mindist=value.  Sets  the  minimum separation between all nodes. If not
   specified then circo uses a default value of 1.0.

   (fdpspecific attributes)
   K=val. Sets the default ideal node separation in the layout.

   maxiter=val. Sets the maximum number of iterations used to  layout  the
   graph.

   start=val.  Adjusts  the  random  initial  placement  of  nodes with no
   specified position.  If val is is an integer, it is used  as  the  seed
   for  the  random  number generator.  If val is not an integer, a random
   system‐generated integer, such as the process ID or  current  time,  is
   used as the seed.

  Node Attributes
   height=d   or   width=d   sets   minimum   height   or  width.   Adding
   fixedsize=true forces these to be the  actual  size  (text  labels  are
   ignored).

   shape=record polygon epsf builtin_shape
   builtin_polygon  can  be plaintext ellipse oval circle egg triangle box
   diamond trapezium parallelogram house hexagon octagon  note  tab  box3d
   component,  among  others.   (Polygons  are  defined or modified by the
   following node attributes: regular,  peripheries,  sides,  orientation,
   distortion  and skew.)  epsf uses the node's shapefile attribute as the
   path name of an external EPSF file to be automatically loaded  for  the
   node shape.

   See    http://www.graphviz.org/content/node-shapes   for   a   complete
   description of node shapes.

   label=text where text may include escaped newlines \n, \l,  or  \r  for
   center, left, and right justified lines.  The string '\N' value will be
   replaced by the node name.  The string '\G' value will be  replaced  by
   the  graph  name.   Record  labels  may  contain  recursive  box  lists
   delimited by { | }.  Port identifiers in labels are set  off  by  angle
   brackets < >.  In the graph file, use colon (such as, node0:port28).

   Graphviz  also  supports  special  HTML-like  labels  for  constructing
   complex  node  content.  A  full‐description  of  these  is  given   at
   http://www.graphviz.org/content/node-shapes#html.

   fontsize=n sets the label type size to n points.

   fontname=name sets the label font family name.

   color=colorvalue  sets the outline color, and the default fill color if
   style=filled and fillcolor is not specified.

   fillcolor=colorvalue sets the fill color  when  style=filled.   If  not
   specified,  the  fillcolor when style=filled defaults to be the same as
   the outline color.

   fontcolor=colorvalue sets the label text color.

   A colorvalue may be  "h,s,v"  (hue,  saturation,  brightness)  floating
   point numbers between 0 and 1, or an X11 color name such as white black
   red green blue yellow magenta cyan or burlywood, or a  "#rrggbb"  (red,
   green, blue, 2 hex characters each) value.

   style=filled solid dashed dotted bold invis or any Postscript code.

   href="url"  sets  the  url for the node in imagemap, PostScript and SVG
   files.  The substrings '\N' and '\G' are substituted in the same manner
   as  for  the  node label attribute.  Additionally the substring '\L' is
   substituted with the node label string.

   URL="url" ("URL" is a synonym for "href".)

   target="target" is a target string for client‐side imagemaps  and  SVG,
   effective  when  nodes  have  a  URL.   The  target  string  is used to
   determine which window of the browser is used for the URL.  Setting  it
   to  "_graphviz"  will open a new window if it doesn't already exist, or
   reuse it if it does.  If the target string is empty, the default,  then
   no target attribute is included in the output.  The substrings '\N' and
   '\G' are  substituted  in  the  same  manner  as  for  the  node  label
   attribute.   Additionally  the  substring  '\L' is substituted with the
   node label string.

   tooltip="tooltip" is a tooltip string  for  client‐side  imagemaps  and
   SVG,  effective  when nodes have a URL.  The tooltip string defaults to
   be the same as the label  string,  but  this  attribute  permits  nodes
   without  labels  to  still have tooltips thus permitting denser graphs.
   The substrings '\N' and '\G' are substituted in the same manner as  for
   the   node   label  attribute.   Additionally  the  substring  '\L'  is
   substituted with the node label string.

   The following attributes apply only to polygon shape nodes:

   regular=n if n is non‐zero then  the  polygon  is  made  regular,  i.e.
   symmetric  about  the  x and y axis, otherwise the polygon takes on the
   aspect ratio of the  label.   builtin_polygons  that  are  not  already
   regular  are made regular by this attribute.  builtin_polygons that are
   already  regular  are  not  affected  (i.e.   they   cannot   be   made
   asymmetric).

   peripheries=n  sets  the  number  of  periphery  lines drawn around the
   polygon.  This value  supersedes  the  number  of  periphery  lines  of
   builtin_polygons.

   sides=n  sets  the  number  of  sides to the polygon. n<3 results in an
   ellipse.  This attribute is ignored by builtin_polygons.

   orientation=f sets the orientation of the first  apex  of  the  polygon
   counterclockwise  from  the  vertical, in degrees.  f may be a floating
   point number.  The orientation  of  labels  is  not  affected  by  this
   attribute.   This  attribute  is  added  to  the initial orientation of
   builtin_polygons.

   distortion=f sets the amount of broadening of the top and narrowing  of
   the  bottom  of  the  polygon  (relative to its orientation).  Floating
   point values between -1  and  +1  are  suggested.   This  attribute  is
   ignored by builtin_polygons.

   skew=f  sets  the  amount  of  right‐displacement  of the top and left‐
   displacement  of  the  bottom  of  the   polygon   (relative   to   its
   orientation).   Floating  point values between -1 and +1 are suggested.
   This attribute is ignored by builtin_polygons.

   (circospecific attributes)
   root=true/false. This specifies that the  block  containing  the  given
   node be treated as the root of the spanning tree in the layout.

   (fdpspecific attributes)
   pin=val.  If  val  is  "true",  the  node  will  remain  at its initial
   position.

  Edge Attributes
   minlen=n where n is an integer factor that applies to the  edge  length
   (ranks for normal edges, or minimum node separation for flat edges).

   weight=n  where n is the integer cost of the edge.  Values greater than
   1 tend to shorten the edge.   Weight  0  flat  edges  are  ignored  for
   ordering nodes.

   label=text  where  text  may include escaped newlines \n, \l, or \r for
   centered, left, or right justified lines.  If  the  substring  '\T'  is
   found  in  a  label  it will be replaced by the tail_node name.  If the
   substring '\H' is found in a label it will be replaced by the head_node
   name.   If  the  substring  '\E'  value  is found in a label it will be
   replaced by: tail_node_name->head_node_name If the  substring  '\G'  is
   found  in  a  label  it  will  be  replaced  by the graph name.  or by:
   tail_node_name--head_node_name for undirected graphs.

   fontsize=n sets the label type size to n points.

   fontname=name sets the label font family name.

   fontcolor=colorvalue sets the label text color.

   style=solid dashed dotted bold invis

   color=colorvalue sets the line color for edges.

   color=colorvaluelist  a  ':'  separated  list  of  colorvalue   creates
   parallel edges, one edge for each color.

   dir=forward back both none controls arrow direction.

   tailclip,headclip=false disables endpoint shape clipping.

   href="url"  sets  the  url for the node in imagemap, PostScript and SVG
   files.  The substrings '\T', '\H', '\E' and '\G' are substituted in the
   same  manner  as  for  the  edge  label  attribute.   Additionally  the
   substring '\L' is substituted with the edge label string.

   URL="url" ("URL" is a synonym for "href".)

   target="target" is a target string for client‐side imagemaps  and  SVG,
   effective  when  edges  have a URL.  If the target string is empty, the
   default, then no target attribute  is  included  in  the  output.   The
   substrings '\T', '\H', '\E' and '\G' are substituted in the same manner
   as for the edge label attribute.  Additionally the  substring  '\L'  is
   substituted with the edge label string.

   tooltip="tooltip"   is  a  tooltip  string  for  client‐side  imagemaps
   effective when edges have a URL.  The tooltip string defaults to be the
   same  as  the  edge  label string.  The substrings '\T', '\H', '\E' and
   '\G' are  substituted  in  the  same  manner  as  for  the  edge  label
   attribute.   Additionally  the  substring  '\L' is substituted with the
   edge label string.

   arrowhead,arrowtail=none, normal, inv, dot, odot, invdot, invodot, tee,
   empty, invempty, open, halfopen, diamond, odiamond, box, obox, crow.

   arrowsize                                 (norm_length=10,norm_width=5,
   inv_length=6,inv_width=7,dot_radius=2)

   headlabel,taillabel=string          for          port           labels.
   labelfontcolor,labelfontname,labelfontsize  for  head  and tail labels.
   The substrings '\T', '\H', '\E' and '\G' are substituted  in  the  same
   manner  as  for  the  edge label attribute.  Additionally the substring
   '\L' is substituted with the edge label string.

   headhref="url" sets the url for the head port in  imagemap,  PostScript
   and   SVG  files.   The  substrings  '\T',  '\H',  '\E'  and  '\G'  are
   substituted in the  same  manner  as  for  the  edge  label  attribute.
   Additionally  the  substring  '\L'  is  substituted with the edge label
   string.

   headURL="url" ("headURL" is a synonym for "headhref".)

   headtarget="headtarget" is a target string  for  client‐side  imagemaps
   and  SVG,  effective when edge heads have a URL.  The headtarget string
   is used to determine which window of the browser is used for  the  URL.
   If  the  headtarget  string  is  empty,  the  default,  then headtarget
   defaults to the same value as target  for  the  edge.   The  substrings
   '\T', '\H', '\E' and '\G' are substituted in the same manner as for the
   edge label attribute.  Additionally the substring '\L'  is  substituted
   with the edge label string.

   headtooltip="tooltip"  is  a  tooltip  string for client‐side imagemaps
   effective when head ports have a URL.  The tooltip string  defaults  to
   be  the  same  as the headlabel string.  The substrings '\T', '\H', and
   '\E' are  substituted  in  the  same  manner  as  for  the  edge  label
   attribute.   Additionally  the  substring  '\L' is substituted with the
   edge label string.

   tailhref="url" sets the url for the tail port in  imagemap,  PostScript
   and   SVG  files.   The  substrings  '\T',  '\H',  '\E'  and  '\G'  are
   substituted in the  same  manner  as  for  the  edge  label  attribute.
   Additionally  the  substring  '\L'  is  substituted with the edge label
   string.

   tailURL="url" ("tailURL" is a synonym for "tailhref".)

   tailtarget="tailtarget" is a target string  for  client‐side  imagemaps
   and  SVG,  effective when edge tails have a URL.  The tailtarget string
   is used to determine which window of the browser is used for  the  URL.
   If  the  tailtarget  string  is  empty,  the  default,  then tailtarget
   defaults to the same value as target  for  the  edge.   The  substrings
   '\T', '\H', '\E' and '\G' are substituted in the same manner as for the
   edge label attribute.  Additionally the substring '\L'  is  substituted
   with the edge label string.

   tailtooltip="tooltip"  is  a  tooltip  string for client‐side imagemaps
   effective when tail ports have a URL.  The tooltip string  defaults  to
   be  the  same as the taillabel string.  The substrings '\T', '\H', '\E'
   and '\G' are substituted in the same  manner  as  for  the  edge  label
   attribute.   Additionally  the  substring  '\L' is substituted with the
   edge label string.

   labeldistance and labelangle (in degrees CCW) specify the placement  of
   head and tail labels.

   decorate draws line from edge to label.

   samehead,sametail  aim  edges  having  the same value to the same port,
   using the average landing point.

   constraint=false causes an edge to be ignored for rank assignment.

   layer=id or id:id or "all" sets the edge's active  layers.   The  empty
   string means no layers (invisible).

   (neatospecific attributes)
   w=f  sets the weight (spring constant) of an edge to the given floating
   point value.  The default is 1.0; greater values  make  the  edge  tend
   more toward its optimal length.

   len=f sets the optimal length of an edge.  The default is 1.0.

   (fdpspecific attributes)
   weight=f  sets the weight of an edge to the given floating point value.
   The default is 1.0; greater values make the edge tend more  toward  its
   optimal length.

COMMANDLINE OPTIONS
   -G sets a default graph attribute.
   -N sets a default node attribute.
   -E  sets  a  default edge attribute.  Example: -Gsize="7,8" -Nshape=box
   -Efontsize=8

   -lfile loads custom PostScript library  files.   Usually  these  define
   custom  shapes  or  styles.   If  -l  is  given by itself, the standard
   library is omitted.

   -Tlang sets the output language as described above.

   -n[1|2]  (no‐op)  If  set,  neato  assumes  nodes  have  already   been
   positioned and all nodes have a pos attribute giving the positions.  It
   then performs an  optional  adjustment  to  remove  node‐node  overlap,
   depending  on  the  value  of  the overlap attribute, computes the edge
   layouts, depending on the value of the splines attribute, and emits the
   graph  in  the  appropriate  format.  If num is supplied, the following
   actions occur:
       num = 1
   Equivalent to -n.
       num > 1
   Use node positions as specified, with no adjustment to remove node‐node
   overlaps,  and  use  any  edge  layouts  already  specified  by the pos
   attribute.  neato computes an edge layout for any edge  that  does  not
   have  a  pos attribute.  As usual, edge layout is guided by the splines
   attribute.

   -Klayout override the default layout  engine  implied  by  the  command
   name.

   -O  automatically generate output filenames based on the input filename
   and the -T format.

   -P generate a graph of the currently available plugins.

   -v (verbose) prints various information useful for debugging.

   -c configure plugins.

   -m memory test (observe no growth with top, kill when done).

   -qlevel set level of message suppression. The default is 1.

   -sfscale scale input by fscale, the default is 72.

   -y invert y coordinate in output.

   -V (version) prints version information and exits.

   -? prints the usage and exits.

   A complete description of the available  command‐line  options  can  be
   found at http://www.graphviz.org/content/command-line-invocation.

EXAMPLES

   digraph test123 {
           a -> b -> c;
           a -> {x y};
           b [shape=box];
           c [label="hello\nworld",color=blue,fontsize=24,
                fontname="Palatino-Italic",fontcolor=red,style=filled];
           a -> z [label="hi", weight=100];
           x -> z [label="multi-line\nlabel"];
           edge [style=dashed,color=red];
           b -> x;
           {rank=same; b x}
   }

   graph test123 {
           a -- b -- c;
           a -- {x y};
           x -- c [w=10.0];
           x -- y [w=5.0,len=3];
   }

CAVEATS

   Edge splines can overlap unintentionally.

   Flat  edge  labels  are  slightly broken.  Intercluster edge labels are
   totally broken.

   Because unconstrained optimization is employed, node boxes can possibly
   overlap  or  touch unrelated edges.  All existing spring embedders seem
   to have this limitation.

   Apparently reasonable attempts to pin nodes or adjust edge lengths  and
   weights can cause instability.

AUTHORS

   Stephen C. North <north@research.att.com>
   Emden R. Gansner <erg@research.att.com>
   John C. Ellson <ellson@research.att.com>
   Yifan Hu <yifanhu@research.att.com>

   The   bitmap   driver   (PNG,   GIF   etc)   is   by   Thomas  Boutell,
   <http://www.boutell.com/gd>

   The Truetype font renderer is from the Freetype Project (David  Turner,
   Robert   Wilhelm,   and  Werner  Lemberg)  (who  can  be  contacted  at
   freetype-devel@lists.lrz-muenchen.de).

SEE ALSO

   This man page contains only a small amount of the  information  related
   to  the  Graphviz layout programs. The most complete information can be
   found at http://www.graphviz.org/Documentation.php, especially  in  the
   on‐line  reference pages. Most of these documents are also available in
   the doc and doc/info subtrees in the source and binary distributions.

   dotty(1),tcldot(n),xcolors(1),libgraph(3).

   E. R. Gansner, S. C. North,  K.  P.  Vo,  "DAG  ‐  A  Program  to  Draw
   Directed  Graphs",  Software ‐ Practice and Experience 17(1), 1988, pp.
   1047‐1062.
   E. R. Gansner, E. Koutsofios, S. C. North,  K. P. Vo, "A Technique  for
   Drawing  Directed  Graphs,"  IEEE Trans. on Soft. Eng. 19(3), 1993, pp.
   214‐230.
   S. North and E.  Koutsofios,  "Applications  of  graph  visualization",
   Graphics Interface 94, pp. 234‐245.
   E.R.  Gansner  and  E. Koutsofios and S. C. North, "Drawing Graphs with
   dot," Available at http://www.graphviz.org/pdf/dotguide.pdf.
   S.     C.     North,     "NEATO     User's     Manual".       Available
   http://www.graphviz.org/pdf/neatoguide.pdf.

                             12 July 2013                           DOT(1)





Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.