Linux was most of it but it needed hardware to run on. I wrote in another comment in this thread that our semiconductor design software was all on Solaris. We

Linux was most of it but it needed hardware to run on. I wrote in another comment in this thread that our semiconductor design software was all on Solaris. We started shifting to Linux around 2002. We still needed some Suns for the large jobs that required over 4GB RAM. When AMD64 came out that was the end of Sun for us. The chip design software vendors quickly ported to it.