After a few Release Candidates, Merb 1.0 is now available. The installation is simple:
gem install merb
Note: Merb needs RubyGems 1.3.0 (refer to these instructions in case the update to RubyGems 1.3 doesn't seem to work).
A few changes and fixes were added between the release of Merb RC1 and the final release. One example is improved support on JRuby and Windows.
Merb on JRuby now has support for Merb's action arguments, which use ParseTree to get the formal arguments of a method. This information is used to map parameters in the action request to the parameters of the methods. As ParseTree does not work under JRuby (it uses native extensions), a JRuby specific workaround was implemented.
As ParseTree's not available on Ruby 1.9, Yehuda Katz proposed a new API to fetch formal arguments of a method on the ruby-core mailing list.
Yehuda Katz lists more of the changes between RC1 and the final 1.0 version.
Finally, EngineYard has announced to offer Merb Support, starting later in November. The company has been sponsoring Rubinius and Merb for some time (both Ezra Zygmuntowicz (creator of Merb) and Yehuda Katz are EngineYard employees).
