Convex is a stack-based golfing esolang based on Golfscript and CJam. Convex adds many new operators and removes many two-character operators.
HUGE thanks to aditsu for allowing me to use the CJam codebase to get me started on this project!
The biggest difference from CJam is implicit input. Standard input will automatically be placed on the stack in a string form, or converts to list/number/block if applicable. Additionally, Convex uses the CP-1252 encoding, which allows for many more options for operators, meaning that many two-character operators can now be represented in one character. Finally, the other major difference is REGEX. Convex fully supports regex and regex functions.