I'm pretty sure that if Python had a slightly easier deployment option it would replace several of the other scripting languages in my toolbox. The main pain points for me right now are the Python 2 vs 3 split (only a problem because I'm frustrated by uncertainty), and insufficiently clear ways to package apps for deployment (I'd really like to be able to deploy a tool as a single file executable) without having to install a separate version of python on the target machine.

Right now I'm considering Prolog for a project, because I just can't find anything else that does what it does as easily - essentially fact chaining and logical interferencing. But I'm just planning to use it as a part of a system rather than the entire application.