The Silicon Graphics IRIX edition of Praat will work on Indigo, Indy, Onyx, O2, and others.
We have stopped creating new versions of Praat for Silicon Graphics IRIX. If you have an SGI workstation, you can still create a new version yourself directly from the source code. The last version that we did create was 4.1:
Unpack with gunzip and tar xvf. This will create the executable file praat. You can remove the tar file.
To tune your (older) SGI to Praat (and many other programs that use memory!), remove any virtual swap space. This will benefit all programs that use calloc:
swap -d /.swap.virtual
Note that the real swap space, also known as virtual memory, will still exist after this.
Tell me whether this was necessary on your computer, i.e. whether /.swap.virtual did exist when you first downloaded Praat.