I was browsing SCO's website trying to figure out development tool options for SCO OpenServer 5.0.6 (I know, I know) and stumbled across this.
It describes one of the three options for OpenServer 5.0.7 as:
- GNU Development Tools, located on the SCO OpenServer base CD-ROM, is intended for the development of new applications, including Open Source-based code. This kit includes the GNU compilers, debugger, object tools, and other Open Source tools. These tools are license-free.