If you are planning to develop a CBR system you may find some useful help in the Case-Based Reasoning Product Experience Base (CBR-PEB) - this on-line system lets you find information on CBR systems similar in specification to your own.
The following companies all sell CBR tools (and usually offer consultancy). Each link gives a description of the tools, its application suitability, platforms supported and contact information.
If you're looking for an AI tool not listed here try the G6G Directory of Intelligent Software.
The following organisations all provide CBR consultancy.
The following sites have CBR tools that are in the public domain (freeware). Some have restrictions on commercial use.
MLNET maintains an extensive list of ML tools, many of which are free for academic use.