GameMonkey Script

It doesn't say how and what to compile in the source package, and it doesn't even have any makefiles. So how to compile it (on 64-bit Arch Linux, if it matters)?

Welcome to the forum MTK358 My package doesn't contain a make file or even a MSVC project for GM for various reasons. Compiling GM to use with your project should be straight forward and look something like this (Mostly copied from GameMonkeyFAQ.pdf)...

1) Add all the src\gm *.cpp and *.h files to your project except gmDebugger.
(gmDebugger is only required to create a specific debugger application.)
2) Add or create a platform config file such as src\platform\win32gcc\gmConfig_p.h.
3) Add some ready made bindings and helpers from src\binds as you desire.
4) Compile these files with your project, or build and link them as a separate lib.

Let us know how you go or if you run into any problems.

I did more research and decided on a different scripting langauge.

Fair enough. The popular alternatives tend to be Lua and Python. GM often attracts programmers who enjoy C style syntax and fairly simply binding or interfacing between the languages. All the best to you