Hackers have managed to get Amazon's proxy-based Silk browser compiled into other Android versions, allowing anyone* to take advantage of the Amazon cloud.
The hack requires a rooted device, and some mucking about with apk files, but does share the Silk love. XDA-Developers member TyHi initially hacked the Silk browser into the popular CyanogenMod Android distribution, but others have tested it on a wide variety of builds and devices – though there appears to be no reason to bother beyond the joy of seeing what can be done.
Silk offloads most of the rendering of web pages onto the cloud, improving performance and reducing the bandwidth required, but it is far from alone in taking that approach. SkyFire and Bolt work the same way, as does Opera's Turbo option, and Opera has even gone on record promising not to misuse the accumulated data.
So the only reason for wanting to run Silk would seem to be a desire to let Amazon know more about one's browsing habits, as though the company hasn't accumulated enough information on everything one buys, or thinks about buying.
So this is just a hack to demonstrate what can be done, which is an admirable thing in itself and to be respected. But for most users Silk has little to offer beyond what's already available, with rather less effort. ®
* Anyone with a compatible handset, and a desire to root it too.