I would like to provide a very simple scripting interface for a program I'm working on. My program would expose some functions that could be called from the script. I don't need much, maybe just variables, if/else, and loops. The two most popular languages seem to be lua, and python. I really do not like lua from my days of writing World of Warcraft plugins and both seem a lot more complicated than I need. What other languages are available?
Try the Ring programming language (http://ring-lang.net)
The compiler + The Virtual Machine are 15,000 lines of C code
The Ring can be embedded in C/C++ projects, extended using C/C++ code and/or used as standalone language.
The language is simple, trying to be natural, encourage organization and comes with transparent implementation. It comes with compact syntax and a group of features that enable the programmer to create natural interfaces and declarative domain-specific languages in a fraction of time. It is very small, fast and comes with smart garbage collector that puts the memory under the programmer control. It supports many programming paradigms, comes with useful and practical libraries. The language is designed for productivity and developing high quality solutions that can scale.
Learn about embedding the language from https://en.wikibooks.org/wiki/Ring/Lessons/Embedding_Ring_Interpreter_in_C/C%2B%2B_Programs