I've heard good things about MOCL but haven't tried it myself, and I know getting ECL working on mobile is an uphill battle (but achievable if you have the time). ECL switched maintainers recently, so maybe mobile is something they will focus on in the future.
I run Linux on my web servers but develop from a Windows desktop. CCL works great on both.
Also, it's the best free CL for targeting Raspberry Pi - unlike SBCL, CCL supports native threads there, and with the weak but quad-core processor of RPi2, the difference is very noticeable.
I don't think the developers have worked around that, though I have seen some conversation about it in the past. My limited Google searches on the subject today didn't suggest that anything has changed since the last time I looked at it.
Edit:
Oh, duh, I already said all of this about 4 1/2 years ago:
https://news.ycombinator.com/item?id=1804415
Visiting the system requirements page again suggests the limitation still exists:
That's not usually a showstopper for me, though.