Making tree-diagrams with pdf output without using graphviz

I usually like graphviz a lot for making graphs and trees and outputting them to pdf files. Right now I have a program that builds a tree with a large branching factor (up to 12, usually closer to 8 or 9). The problem is that graphviz cannot draw the tree more than two or three levels deep (and less if I use my fancy labels).

My train of thought is that this is a very simple graphic to generate. It's a very generic tree structure and no specialized placement algorithms are needed at all. I'm wondering if anybody knows of another software package that might get the job开发者_如何转开发 done. Here are the features I'm looking for:

Bare minimum:

• Draws really wide trees with many vertices (perhaps a few million)
• Outputs to pdf, postscript, svg, or some other common, portable graphics format

Good to have:

• input format similar to graphviz
• nodes that can be colored
• html-style tables, similar to the awesome ones that graphviz has

Have you considered TikZ? http://www.texample.net/tikz/examples/tag/graphs/

I have not had to make graphs with millions of nodes, so I can't be sure this will work.

I originally suggested, in a comment, that graphviz provided facilities to produce multi-million node graphs. The rendering engine I was thinking of was sfdp, which is supplied as part of the graphviz package. An example is provided in the Graphviz gallery. As far as I am aware, this can be used with all the normal Graphviz output facilities.