Regarding the versions, the Pauli Algebra Package Workbook available in MapleCloud is the latest version.
I was unable to repair the original package, so I deleted it and reuploaded a second copy. I forgot to update this thread about the outcome, forgetting that forums is a typical portal to my work--so I give you my sincerest of apologies.
As for other geometric algebra packages, I am vaguely familiar with them. I tried using one but I had hang ups with e1, e2 and e1e2 being unique elements, I would much prefer e1e2 being defined as e1 and e2 with a non-commutative multiplication operator instead. (Maplesoft, if you're listening, let me use * instead of . please!)
After reviewing the Maple Programming Manual, I realized that much of what I wanted to do with APS (Cl3) can be done with a custom data type, the Paravector. With a little OOP and the work of Dr. W.E. Baylis, I could covert common Maple datatypes to a Paravector, use the Pauli Algebra to my heart's content, then convert them back so I can continue using Maple. It's still my favorite package in Maple when teaching highschool physics!
 Baylis W.E. (1996) Pauli-Algebra Calculations in MAPLE V. In: Abłamowicz R., Parra J.M., Lounesto P. (eds) Clifford Algebras with Numeric and Symbolic Computations. Birkhäuser, Boston, MA