You'll be fine, but make sure you download it via the official ProjectLibre download page:
Question: Q: Is ProjectLibre for Mac safe to be installed? This site contains user submitted content, comments and opinions and is for informational purposes only. Apple may provide or recommend responses as a possible solution based on the information provided; every potential issue may involve several factors not. Projectlibre was founded to provide both a Cloud replacement of Microsoft Project and an open source replacement of Microsoft Project desktop. We have succeeded in that mission with over 4,700,000 desktop downloads but will soon also offer a revolutionary cloud solution, ProjectLibre Cloud. ProjectLibre has a lengthy list of Fortune 500, Government, small business and non-profits utilizing our comprehensive project management features. ProjectLibre has been translated into 20 languages. Watch Demo ProjectLibre is compatible with Microsoft Project 2003, 2007 and 2010 files. You can simply open them on Linux, Mac OS or Windows.
The first time you open it you need to exempt it from Gatekeeper by right-clicking an selecting 'Open' from the contextual menu as described here:
Apple doesn't really 'certify' third-party software as such. Pretty much anybody can buy a code-signing certificate from Apple for $100/year, which suppresses one level of Gatekeeper warnings. If the App also complies with various restrictions it can be distributed via the App store, which suppresses the next level of Gatekeeper warnings. For various reasons (some ideological, some technical, etc.) it is not uncommon for open source projects not to jump these hurdles.
Projectlibre For Mac 10.6
C.
Teamwork (Free Forever Plan) Although Teamwork (formerly known as Teamwork Projects) is a. ‎XPlanner is a tool for lean project management that improves the personal or team productivity. It allows to see the big picture, and speed the implementation. Its main features are: - Visual and clear overview of your tasks - Drag and drop tasks between columns easily - Limit your work in progress.