Nonprofit member management software ?


Nov 4, 2015
Hello, I work as a volunteer for nonprofit organizations. One of them manages its members online :memberships, membership fees, accounting, mass mailings... But I definitely don't trust the website (I don't have any access to the database, the thing is really obsolete and the site is often down). I'd rather like to create my own database on a server of my choice, or why not offline if I can find a software that can run on Windows, Mac and Linux (absolutely necessary) and easily backup and export data so several persons can work on it. We're quite small, so we don't have a big budget, but hosting isn't a problem, only the software price is. We speak French so if the software is already translated or I can easily translate it, it would be really great.
I'd like to thank in advance anyone who can suggest a software for us :)