This project hosts various plugins for the OpenCPN chart plotter, which are not bundled with the core package.
OpenCPN is a free software (GPLv2) project to create a concise chart plotter and navigation software, for use underway or as a planning tool. OpenCPN is developed by a team of active sailors using real world conditions for program testing and refinement.
Vifir processes and displays electronic aviation charts (currenty VFR Sectional Charts) produced by the U.S. National Aeronautical Charting Office in a similar way to an Electronic Flight Bag.