A lot of people have mappings like jk or jj to escape insert mode. The problem with these mappings is that whenever you type a j, neovim wait about 100-500ms (depending on your timeoutlen) to see if you type a j or a k because these are mapped. Only after that time, the j will be inserted. Then you always get a delay when typing a j.
...VCLua allows a program to be executed on different os systems without any modification.
VCLua can be compiled with the Free Pascal based Lazarus compiler into one easy portable file.
To use VCLua you'll need only the Lua script interpreter.
VCLua currently tested on Windows and Linux.