This format can...
read and write tracks
This format is derived from the xcsv format, so it has all of the same options as that format.
This is the format used by the software that comes with the Transystem i-Blue747 GPS.
Notice that the iBlue 747 logs the sum of "height above sealevel" and "height of geoid above WGS84". If precise altitude matters to you, check out the height filter which allows you to compensate for this.