I have files in .kml format. In windows 7 I opened them with Google Earth, but Google earth for Linux wrongly determines the place of workout on map.
What application can I use to work with these files?
If you're having problems with Google Earth in Ubuntu then you could try using Google Maps to view your .kml files.
To view a KML or KMZ file on Maps, just go to Google Maps, and instead of searching for a geographical address like 1600 Amphitheatre Parkway, 94043, search for a complete Web address (including the "http://" part) of your KMZ file, like http://kml.lover.googlepages.com/cropcircles.kmz. Need your own web space to upload some files? Try Google Page Creator.
Google Page Creator has been shut down and Google now encourages to use Google Sites instead.
GPSPrune claims to support KML for read, view, edit and saving. It is java application and available for linux:
GpsPrune is a free, open source, cross-platform program to view and edit coordinate data like GPS tracks.
Viewing data with a map view using OSM maps
Editing data (delete individual points or sections, variable compression, combine and rearrange data, create and edit individual points)
GpsPrune can read files in the following formats: kml, including zipped and gzipped kml files and kmz files
GpsPrune can also save data to files in the following formats: kml and kmz files (kmz files can include photo thumbnails)
I also suggest to use a free conversion tool, like this one: kml2gpx.com to convert them into gpx files. It is a simple and convenient way to get the results you need.
For even more possibilities, you can try OSGeoLive, a Xubuntu-based live DVD loaded with GIS software.