How can I get some display feature (such as bold lines) in dotty?
Dotty has not really changed for many years. Therefore, there are myriad features available in Graphviz which it cannot handle. In some cases, you can use Grappa or webdot for display instead of dotty. For example, Grappa has generalized polygons (node [shape=polygon]) that dotty lacks. There are additional interactive viewers available. For example, see Graphical Interfaces and Viewers. If you are using Mac OS X, the Mac version of Graphviz has a highly recommended GUI.
If the display attribute that you need isn't there already, in dotty, there's probably no easy way to do it except by rolling up your sleeves and hacking the dotty code (a lefty script) that interprets and renders graphical attributes. This is problematic for the same reason as above: there's no universal low-level driver layer shared across all the Graphviz tools. We recently added an intermediate rendering language to the layout tools, but the various front ends don't use it yet. This would be a good project for someone who wants to get involved here (along with porting dotty to GTK.)
GraphvizWiki: FacDottyMissingFeature (last edited 2008-01-17 18:11:12 by H-135-207-131-158)