Working as a developer I use a lot of tools and software every day. This is an incomplete list showcasing which ones work best for me.
Comparsion of compilation times on Gentoo on different hardware and with different use flags.
Setting up a microphone for podcasting or conferences can be quite tricky. Most people make some pre-recordings to achieve that. But there is also an easier way on Linux by listening to your own microphone with a delay.
Automatically testing graphical web applications in an continous integration environment can be quite troublesome in certain cases.