This page describes the basics of OSM. For more detail, go to the wiki (link above). To ask a question, post an Issue (also above). You may be here, but actually looking for specific projects, like Series 4 or Series 3 or maybe even the published Series 1.
OSM is for anyone interested in working on malaria in an open source manner. "Open source" means that you work in line with the Six Laws. The most important of these is that all data and ideas are freely shared, anyone may participate and there will be no patents. While OSM has a current focus on the discovery and development of new medicines, it is intended as a platform for any malaria-related research.
There is a basic Landing Page which imports activity, but is not human-curated. Social media updates go to Twitter.
Electronic Lab Notebooks (ELNs). These are the bedrock of OSM, since everything that is done is recorded in real time. There are many ELNs, depending on where researchers put them. To find them, go to the relevant project wikis, where there ought to be a "sources of data" link that will take you there. e.g. for Series 3 or Series 4.
OSM Molecules are on the Master List.
Discussion/File Sharing: Github (what you're looking at) is used for this. Different parts of OSM have different "repositories" or "repos", from the About one (what you're looking at) to the specific (such as the repo for Series 4). Discussion takes place by posting, and replying to, Issues (link above). To contribute, get a Github account. It's easy and non-spammy.
There is an old Google+ community that could be resurrected. There is an email address (opensourcemalaria@gmail.com) but email is discouraged because it is bilateral.