I used to have a program with an embedded Lua interpreter where I sometimes needed to switch back and forth between C++ and Lua. It's insane. Arrays don't start at zero, you create blocks with keywords and then there are some minor annoyances like != being ~= or the lack of a ternary operator. Where Lua really shines though is the binding api. It's really easy to use when you have to do something by hand. The documentation is great and you have a selection of binding tools. You can even create classes with overridable virtual methods.

Since Lua is rather tedious to use for me, I looked for alternatives with a C-like syntax. I found Squirrel and Wren but the last time I looked they lacked the tooling and mailing lists that Lua already has. It's a bit of a chicken-egg problem unfortunately.