Found this interesting snippet part way down the page at https://rara.com/help/en/faq.html

"What platforms are supported by rara.com?

rara.com can run on any PC with a supported web browser. rara.com has been tested with Windows XP SP2 and above, Mac OS 10.4 and above, and HP WebOS."

In publicity there's some mention of this service being built into HP PCs in the future so I guess they have some special relationship with HP and thus the specific mention of WebOS.

Heh, I wonder whether Rara.com access will be built right into the next WebOS version?

Has anyone in one of the supported countries tried it on a WebOS device yet? It's based on the same music library engine as Sony's "Music Unlimited" which IMHO is an excellent service - but Rara is cheaper.