With Microsoft shutting down their code repository, CodePlex, recently and conceding that coders prefer GitHub, it's interesting to look at what projects coders from around the world are looking at. Felipe Hoffa, a developer advocate at Google, has done some analysis to find out what the most popular GitHub projects with a country-by-country analysis.
You'll need to scroll down a fair way in his analysis to find the Australian data. When you get there, you'll learn - perhaps surprisingly - that relax/relax, a CMS, is most popular.
US and Canadian developers seem keen on financial services projects while developers in many countries are simply looking for code optimisation and other ways to improve their own work.
At a global level, FreeCodeCamp is easily the most popular project.
Hoffa's work is worth looking at as it may point you to projects that could be of value but you weren't aware of before.