NEW Mathematica notebooks by Richard Shaw
CAMB uses variables derived from covariant quantities, and the equations (in equations.f90) look superficially different from those in CMBFAST using the synchronous gauge. The equations in the form used by CAMB are derived and presented in Antony's thesis, though the notation there is somewhat unconventional, see also the references in the Readme. Potentially useful resources in Maple 6 text format are:
The initial conditions, initial power spectrum definition, and some other useful relations are given in some provisional notes. This is mentioned here just in case it is useful, even though they are very concise and un-perfected. If you want to write some better docs do let me know!
There is also a maple file of the scalar perturbation equations in an arbitrary frame here.There is also a separate theory page for vector modes.