replacement for GVS

We are in the process of porting a visualzation tool from Irix5.3 to Irix6.5 and then to Linux. The tool was originally writen to use GVS and Irix GL. We are converting the GL to OpenGL and are looking for a replacement for GVS.

Is there an high-level API that would support both platforms and have a minimal (or no) run-time license cost?

Note: this is a re-post of the same question on the Linux board.

You might consider VTree. It’s a C++/OpenGL scene-graph API for Windows 95/NT, Linux, Sun, and IRIX. Runtimes are free for less than 25 copies (per title) and there’s a buy-out above that.
http://www.cg2.com/products/vtree/vtreetemp.htm

You could also try porting to OpenGVS which is OpenGL-based. The cost is much less than it used to be too! OpenGVS runs on ALL platforms (except for Mac last ime I checked) and it is source-code portable across ALL platforms and they even use the SAME makefile!!