I don’t always recommend open source, but in some cases its a must. If you have lots of users (or intend too), then why pay $ per user to some vendor for licences. It’s not just about because its free (as in $0), but it often gives you more flexibility. I have many years experience with open source, including linux, FSF ( I met Richard Stallman recently), and all manner of perl, java, C tools, compiling, merging , using and changing them to meet project needs. Open Source can really drive down barriers, and reduce costs.