Yes and no.  The IBM mainframe adaptation was performed by building the code under VM and bringing it as close as possible to building under MVS at which point the code snapshot was taken over by a company that generally doesn't talk to others about security issues and whose lawyers wouldn't allow the changes they made to go back into the code base -- Open Source has yet to arrive there.
This means that anyone wanting to run cryptlib on IBM mainframes will need to duplicate some of the work they did: system information polling to gather randomness for key generation (random/mvs.c and random/vm.c), miscellaneous code tweaks here and there, and fixing up the JCL. The last two are pretty trivial, the only thing that requires any real work is the randomness polling.  The AS/400 situation is somewhat worse, to date there have been multiple ports performed but none have been released.