It seems that PHP has two memcached libraries named memcache and memcached. What is the difference and how do you know which one to use? Is one outdated? It seems that memcached offers more methods so I would assume that means it has had the most development - but it also seems to require external C/C++ libraries so I'm not sure if I can install it.
It seems that memcache has been around longer, does not require additional libraries, and has pre-compiled binaries for even windows! I would think that it would be the better choice for now. However, being new to memcached (server) I'm not sure if there is some super important features in memcached (php) that make it worth the extra trouble.
Memcached client library was just recently released as stable. It is being used by digg ( was developed for digg by Andrei Zmievski, now no longer with digg) and implements much more of the memcached protocol than the older memcache client. The most important features that memcached has are:
All of this points were enough for me to switch to the newest client, and can tell you that it works like a charm. There is that external dependency on the libmemcached library, but have managed to install it nonetheless on Ubuntu and Mac OSX, so no problems there so far.
If you decide to update to the newer library, I suggest you update to the latest server version as well as it has some nice features as well. You will need to install libevent for it to compile, but on Ubuntu it wasn't much trouble.
I haven't seen any frameworks pick up the new memcached client thus far (although I don't keep track of them), but I presume Zend will get on board shortly.
Zend Framework 2 has an adapter for Memcached which can be found here
When using Windows, the comparison is cut short:
memcache appears to be the only client available.