The EhCache project appears to be having a very busy summer. EhCache 1.5.0 (a major new version) was released on July 12th. In addition, a new (SOAP-based) EhCache Server was released at the end of July. You might ask yourself why you'd need such a beast. I think Greg explains it best:
Why am I doing this? There are lots of theories that have made their way on to the ehcache mailing list. The prosaic truth is that a large US corporate using ehcache for their Java apps on 200+ servers also wants to use it for their C++ apps. And they are prepared to sponsor development. The Web Services API lets them do it. That's it.
As to the larger question of how interesting this is to the world at large, my view is not very. However having to jump through all the hoops to get a server infrastructure done, I thought that the world at large may be interested in a RESTful, resource oriented ehcache server.
The next day, Greg announces EhCache for JRuby on Rails. A few days later, RESTful, resource-oriented caching becomes available in ehcache-server.
I guess this helps answer the question about OSCache vs. EhCache. OSCache hasn't had a release in over a year and EhCache is pumping out new releases and new products. Well done, Greg!
At LinkedIn, we use EhCache for many of our caching needs. However, it's likely we'll be moving to Memcached in the future. Since I'll be part of the team that implements Memcached, it'll be interesting to see which one performs better.