klog is a command line tool for time tracking in a human-readable, plain-text file format. If you want to learn more about it, the documentation website is a good starting point. The CLI app is implemented in Go, and it’s able to evaluate and manipulate
.klg files from the console. You find the source code along with the file format specification on Github. I also maintain a plugin for Sublime Text that provides syntax highlighting and snippets.
[x]it! is a file format for todos and check lists. The syntax rules are described in a formal specification, and the usage is demonstrated on the documentation website. There, you also find a comprehensive directory of third-party tooling. The plugin for Sublime Text, for example, which I maintain, provides syntax highlighting and snippets.