In an article ( link) on CIO.COM LibrePlan is mentioned, amongst others. About the software:
Although most project management software providers offer additional advanced and robust features for an additional cost, these picks have free basic or community offerings with more than enough functionality for most projects. In fact, it should be mentioned that these solutions aren’t just used by small start-ups, many of them are still being used by Fortune 500 companies today due to scalability, powerful features and versatility.
This definitely is true in the case of LibrePlan.