vasFMCfreeware, configurable, always under development, standalone Flight Management Computer.
Current version (altough its still marked as beta) have fully working (2 engine) Airbus-style MCP with EFIS, ND, PFD and upper ECAM, is able to run checklists, and most of FMC work that is needed, including autopilot with autothrottle.
Also have mostly working Boeing (also 2 engine) style version, but MCP is same as in airbus, so its not yet fully configured.
Software runs in separate application window and can be configured to work on LAN (hurray for cockpit builders), its fully compatybile with Xplane9 and FS9 and almost fully compatybile with FSX. FS9 version can be installed as gauges version and incorporated into panel inside plane and not need to be runned in separate window like XPL and FSX versions.
Additional options are build-in TCAS and fully working AIRAC database from Navigraph (altough AIRAC DB is payware after 0613 version - currently we should use 1001 - and new version is available every month).
http://vas-project.org/vasfmc-2x/Using this software can save few $ for getting computer suitable to run Xplane or other sim and second licence for that software. (for LAN in FS need registered FSUIPC and WideFS)
What more? It fully simulates fly by wire on airbus and is fully compatybile with opencockpits FMC and MCP-boeing hardware.
In future versions for sure will be some more-than-2-engine ECAM and boeing-style MCP.