I know that Maple has a PSLQ implementation, but I'd rather not pay for the entire Maple suite just to do Integer Relation problems. I've noticed that Sage links to a python library that does PSLQ, but that library is very limited in that it doesn't give the range of arguments for precision and tolerance that I'd like to be able to explore. Bailey has a GNU C++ library that does PSLQ with arbitrary precision, but I'd rather not be forced to use a command-line interface for experimentation. I like the cleaner presentation available in most CAS products.
I'm especially interested in PSLQ and not LLL simply because PSLQ gives you bounds on the norm of any possible integer relation even when it fails to find one, and this is a useful property. I'd like to explore some approximations to $\pi$ as well as play with some other integer relations among other constants that show up a lot in geometry.
Do you know of any CAS products (free or not) that have a good PSLQ implementation I can use, or are there other alternatives I may have overlooked?