2003: C programming
2006: C++ programming basics
2007 / 2011: Java programming
2011-2013: Ruby programming, SQL databases
2013-2014: C# programming
2015-2018: .NET C# programming, SQL databases
I got started programming games on a console. Writing tools was new ground and I did lots of level editing by hand before I realized how much work a good tool can save you.
So naturally most tools I wrote over the years were related to game projects. For example editing and conversion tools for my game engines.
I've also been working on a toolset to help me when I'm writing. To organize my thoughts, help visualize the story, bring inspiration, and manage my creativity.