I'm currently working on a project that uses Tcl as its primary programming language. One of the great features about the Tcl interpreter is that it lets you introspect things like variables and procedures at runtime. You also get the full source code of procedures at runtime, even those that were themselves defined at runtime. Instead of the normal work flow of having Claude make changes, starting up a web service, testing the web service with some Javascript driver code, I instead work through Claude in Chrome and expose a web-based interpreter from within the running web service itself. I can instruct Claude to make changes at runtime and immediately after making that change, the code can be tested by Claude. Those changes can then be dumped to disk and reincorporated back into the base source code I have. Not something you'd want to expose to the wider internet, but it's let me move _very_ quickly and build out apps within minutes.