DinkLua
0.85 and later contain a port of Phoenix's DinkLua scripting backend. DinkLua is infinitely more powerful than DinkC and contains mind-blowing features such as loops and string variables!
A brief introduction is available from the author here, and a more general Lua tutorial to get you started may be found here, or a short reference here.
Using Lua means that one not only has access to inbuilt libraries for mathematics and string manipulation, but also the entire Lua ecosystem.
The Lua backend is not switched on by default and must be manually enabled in dink.ini. Adding the line dinklua_enable anywhere in dink.ini will switch it on at launch. If one would like to use Lua exclusively, the line dinkc_off may also be specified.
Script execution precedence starts from Lua files in your mod data, followed by those in Dink's data, before looking for DinkC d and c files, assuming DinkC is on as well.
As Lua is a standardised programming language, there are numerous IDEs and text editor plugins that may assist you. One such IDE is ZeroBrane Studio designed specifically for Lua.
In Visual Studio Code, having the init.lua environment file open in another tab will provide some degree of autocomplete.
As a general reminder, most existing DinkC commands are available in the "dink" table. For example DinkC's playmidi() becomes dink.playmidi().
Another potential gotcha is in values that in DinkC are either 1 or 0. These are bools specified as "true" or "false" in Lua.
Please check the DinkLua Object Reference and the Dink table reference for a comprehensive list.
Releases 0.95 and later contain three bundled helper libraries:
Vivid for colour manipulation
Lume which contains some gamedev-oriented helpers
Vector.lua for vectors
These libraries are automatically included in scripts in a way that one may use them as per their documentation without needing any extra setup.