There is also Rubinius, and JRuby. Not to mention a few versions of threaded servers for each. Rubinius + Puma shows huge potential, I am running very large Rails app on a DigitalOcean 512MB ram droplet using it, and not using more than 30% memory.
The problem with your comment is while Javascript has improved and while Rails is still relatively slow, both Rails, Ruby implementations, AND server speed in general has gotten faster AND cheaper.
Not to mention the absolute ease of setting up russian-doll caching throughout with (distributed) memcached, and potential further speedups for all the interpreters (and the upcoming Topaz) and I'd say you presented a very one sided response.
The problem with your comment is while Javascript has improved and while Rails is still relatively slow, both Rails, Ruby implementations, AND server speed in general has gotten faster AND cheaper.
Not to mention the absolute ease of setting up russian-doll caching throughout with (distributed) memcached, and potential further speedups for all the interpreters (and the upcoming Topaz) and I'd say you presented a very one sided response.