I write Lisp programs with an attempt to have them run correctly on as many Lisp implemenations as possible. To do this requires that I test my programs on multiple Lisp platforms. (The main platforms that I use are AllegroCL Enterprise, Lispworks Professional, and CMUCL.)
Peter Van Enyde's Common Lisp Controller package is quite useful for this sort of testing. The basic idea is that you install your source code and system files in a standardized location. Then in your Lisp environment, just give to command (require <pkg>) and the files in your package will be compiled if necessary and loaded into your environment. Common Lisp Controller gives each implementation it's own hierarchical directory structure to store it's compiled code.
Currently, Common Lisp Controller is best supported with Debian GNU/Linux. A nice integration is that when ever you a CLC-aware Lisp package with Debian's package tools, Common Lisp Controller will automatically compile and install the files in the package. Further, when the package is removed, CLC will remove the source and compiled code from the system. I've been working with Peter recently on CLC and it is becoming quite powerful on Debian development (sid/unstable) systems.
