SLIME is an integrated development environment for Common LISP which does everything you would expect from an IDE: code evaluation, compilation, macro expansion, and auto-completion. It also finds definitions of functions, and marks LISP forms which the compiler finds to be erroneous. It provides easy access to implementation-specific online documentation as well as the ability to look up symbols in the ANSI Common Lisp HyperSpec. Further, it includes an interactive debugger and object inspector.
XSLT-process is a minor mode for (X)Emacs that allows you to run a Java XSLT processor on a buffer and display the result in another buffer, or in a browser. You can also run the XSLT processor in debugging mode, setup breakpoints, run step by step, view local and global XSLT variables, and many more.