MAPC2MAPC Help pages : Formats
How to ....
Grids and Datums
Map Images
System Issues

This is my best understanding of GPS systems and the maps that they can read.

Please send updates to calfiles -at-
GPS Software GPS units supported Software for own hand-held device  Calibration
file format
Memory-map Most Pocket-PC and Smart phone JPR
GPSU Nearly all no JPR or TFW(1)
Ozi-Explorer Most Pocket-PC with Windows Mobile/CE MAP, mobile version requires OZF2 map images.
MacGPSPro Most no MAP or JPR
TrekBuddy no Symbian, Palm, Blackberry, Android,
Windows Mobile with JAVA
MAP and special set of images
Fugawi Most Widows Mobile and Palm(4) JPR(2)
Anquet Most Pocket-PC and Windows Mobile Import not supported
Mapyx/Quo Most Pocket-PC TFW
Pathaway Most Windows Mobile and Palm(3) JPR,MAP,TFW or CAL
TouratechQV Most interface to Pathaway CAL
Cartopro Most no MAP, CAL or TFW
GPSTuner no PocketPC GMI(5)
Garmin Garmin Garmin's own KMZ(6) and JNX(8)
Satmap Satmap Satmap's own Import not supported
Tracklogs Some Garmin & Magellan no Import not supported
GPSGO  no Windows Mobile MCD
Viewranger no Symbian 60 Smartphones Import not supported
Mobile Atlas
Many Phones and PDAs including Palm, iPhone and Android
Mobile atlas tiles(7)

Android phones and tablets
MAP calibration and OZF2 image

Android phones and tablets
AQM file contains map and calibration

Android Phones and Tablets SQLitedb file containing Mobile Atlas tiles

Android Phones and Tablets
AQM file containing map and calibration or
MGMaps containing Mobile Atlas tiles
Bitmap and
Maps n Trax

Own format
Gaia GPS

SQLitedb file containing Mobile Atlas tiles

AFTrack (*.osz)
(1) TFW files supported in GPSU version 4.93 and later
(2)  New JPR files created 23May2008 to resolve an incompatibility with Fugawi
(3) Pathaway can be 'fed' from Touratech, Fugawi and Softmap PC software
(4) Fugawi are withdrawing their own handheld software in favour of Pathaway
(5) GPSTuner only accepts JPG images. Download the PNG and use the MapCalibrator downloadable from their website to convert from PNG to JPG
(6) From November 2009 Garmin  have a 'Custom Map' facility on Oregon, Colorado and Dakota devices.   These KMZ files can also be viewed in Google Earth..
(7) See here for a description of Mobile Atlas tiles.
(8) JNX file require an unofficial firmware alteration. More details here