Custom-brewed programming tools, utilities, third-party libraries.
For the recent mobile FMX application development, I had a challenge, do not use any service from my full-featured cross-platform framework, to minimize application bloat, besides, FMX framework itself is rather big piece of cake.
One of the cornerstones is a I18N support which in my framework is based upon custom implementation of gettext. In current case, I decided to wrap I18N manager coode around FMX's TLang. As far as TLang may use, besides its binary stoarage, the plain text files as well, formatted as key=value pair.