QuaternionAlgebra is a package for Maple 8 that makes it possible to perform symbolic manipulations with quaternions. Quaternions are represented by 4x4 matrices, and the package is compatible with the Maple LinearAlgebra package so that matrices and vectors of quaternions can be manipulated. Help files are included, but there is NO WARRANTY.
Here is a PDF copy of a sample worksheet to show what it can do (at a simple
level): QuaternionAlgebraTest.pdf.
The worksheet itself is included with the distribution below, so if you have
Maple 8 or later, you can try it out for yourself.
Installation instructions are included with the package which can be downloaded from here.