> My reasoning is simple. The key for bundling extensions is to have
> them available for most hosting solutions. If a shared host provides
> support for mongodb, then he will most likely enable the mongodb
> extension in php, if he knows what he is doing. The same applies for
> all other non core critical features but more from an architecture
> point of view.
Please don't forget that it's possible to host your database apart from your main code.
Mongolab[1], for example, offers MongoDB hosting, so shared hosts that have the MongoDB extension
enabled could easily use their free tier on cheap hosting (at the cost of latency, of course).
Couch.io[2] used to offer free trial/sandbox hosting of CouchDB, similarly (but there was no stable
CouchDB extension last time I checked), but I'm not sure if Couchbase (to which couch.io now
points) does.
The point is that you don't need to have the target service available on the
PHP-hosting-machine in order to make use of the technology.
[1] https://mongolab.com/
[2] http://www.couchbase.com/
S