scare is a multi-arch assembly REPL and emulator for your command line.
There aren't many modern assembly REPLs out there. The ones that do exist are either opaque webapps, or are tied to specific architecture or platform. scare was built for people who want to test, experiment, or otherwise play with assembly code. All assembled code is run in an emulator, which executes only the code you give it. The multi-architecture design for the underlying scarelib library is meant to be modular, allowing for new architectures to be added quickly.
A shell which acts as a better interactive Python interpreter than the standard Python environment. iPython is designed more for experimentation and playing with ideas prior to implementation than it is for actually developing code. It also supports being embedded in other software for the purpose of extensibility. It even makes it easy to prototype and test GUIs written in Python.