ActiveSupport::Cache vs. others?

Hi,

We are building and using a new caching gem. We would like to figure
out
how to make this most friendly and easy for both existing projects and
new
projects to use. I’m guessing the best way to get used in new projects
would be via subclassing the ActiveSupport::Cache::Store class? Is this
expected to be the primary way to use a cache going forward?

What about gems that may be widely used in existing projects like
cached_fu,
memcached, etc. ? Are these expected to be rolled in through
ActiveSupport::Cache over time?

If you had to chose one cache interface to speak (e.g. drop-in
replacement,
small constructor diff only, or config diff only), which one would you
suggest? And if only two, which two?

Thanks,

Marc