At least Galileo [1] and Beidou [2] are.
Afaik QZSS and NAVIC are not operational (yet), but from what I've heard, QZSS is technically very similar to GPS (signals, not orbits) and should therefore be easy to include.

Edit:
Of course, Glonass is operational too. [3]

[1] http://www.esa.int/Our_Activities/Na...ving_the_globe
[2] http://www.bbc.co.uk/news/technology-20852150
[3] https://glonass-iac.ru/en/GLONASS/index.php