This is an archive of SGI Performer binaries and source. As far as I can tell, the only source released for Performer was for the demos and utility libraries. SGI ported Performer to Windows and Linux and called it "open source". But it wasn't really, and they admitted as much at oss.sgi.com/projects/performer:
Is OpenGL Performer Open Source?
Technically, no. Only the OpenGL Performer samples and utility libraries are included here. Also, our license does not conform to clause 8 of the Open Source Definition.
Currently, this archive only contains SGI's OpenGL Performer 3.0 for Windows. Intriguingly, this Windows version of Performer does include debug libs and PDBs for the core Performer library. So it may be possible to recover Performer source via Ghidra, AI, and some determination.
IRIX and Linux versions may be added later. Note that Performer source can also be found at archive.org, so consider this archive a slightly more friendly mirror of this old code.