Technical aspects ################## * Sage operates in a purely client / server architecture (no network share) on Windows. Users of other systems can use `Parallels Desktop `_ (Mac only) or `VirtualBox `_. * It uses the PostgreSQL database engine. * PostgreSQL can be installed: - on a server (Windows, Linux, MacOS, BSD, AIX, HP / UX, IRIS, Solaris). An automatic installer for Windows is provided. - or on a local station (which must be turned on for users to access). - either at a distance ("Cloud" mode). We propose a database hosting service on powerful servers (XEON 4 cores, 16GB RAM), accessible by certificates (client and server). The databases are backed up daily with a retention period of 15 days. Just allow outgoing connections for client computers via the 5432 / TCP port to a specific address.