Using Pure with Reduce
Reduce is one of the oldest computer algebra systems which has been around since the 1960s and is widely recognized as a state-of-the-art, powerful and efficient CAS. It is free/open source software distributed under a BSD-style license, actively maintained on its SourceForge website, and implementations exist for all major computing platforms.
The pure-reduce module embeds Reduce in Pure, so that the functionality of Reduce becomes available in Pure in a seamless way. More background information and a discussion of the interface can be found in the Embedding REDUCE thread on the Pure mailing list.