QEPCAD is an implementation of quantifier elimination by partial cylindrical algebraic decomposition due orginally to Hoon Hong, and subsequently added on to by many others. It is an interactive command-line program written in C/C++, and based on the SACLIB library. Presented here is QEPCAD B version 1.x, the "B" designating a substantial departure from the original QEPCAD and distinguishing it from any development of the original that may proceed in a different direction. QEPCAD and the SACLIB library are the result of a program of research by George Collins and his PhD students that has spanned several decades ... and continues still!
I extended and improved QEPCAD for several years. Improvements that didn't involve changes to the way the program interacted with the user I'd just go ahead and make. However, changes that affected the interaction of QEPCAD and the user, or changes that added new features were "tacked on" to the program, requiring the user to know about extra commands. Moreover, there was no cannonical source for QEPCAD distribution or documentation, and no internet accessible source at all. This branch of QEPCAD, QEPCAD "B", was introduced to address those problems - to make QEPCAD easily accessable through the internet, to provide good documentation, and to incorporate many improvements and extensions in a way that makes them most accessible to the user.
The principal author of the original QEPCAD is Hoon Hong. Other contributors include: