We are pleased to announce the immediate availability of the 0.4
release of the Grails web application framework. The release can be
obtained from the downloads page: http://grails.org/Download

This release introduces a number of great new features and
improvements to Grails that benefit both the user and its
extensibility. It's been a lot of fun and we're excited to see 0.4
released publicly.

Notable improvements include:

• ORM enhancements with support for more relationship types, easy
  transactions and criteria building, constraints to SQL schema
  mappings, and upgrade to Hibernate 3.2

• All-new non-invasive plugin system for writing reusable plugins for
  Grails applications

• Greater Spring integration thanks to a new syntax for scripting
  Spring (http://grails.org/Spring+Bean+Builder) and an upgrade to
  Spring 2.0

• Easier unit testing of controllers and custom taglibs

• Validation improvements, including support for inherited constraints
  and simplified size constraint handling

• Automatic encoding of unsafe HTML characters and URL parameters in
  all scaffolding and taglibs

• Fixes to support Grails on more containers such as GlassFish and
  over 200 issues and bugs resolved in JIRA
  (http://jira.codehaus.org/browse/GRAILS?report=com.atlassian.jira.plugin.system.project:changelog-panel)

• Grails now ships with Groovy 1.0!

The growing Grails team has spent a huge amount of effort thinking
about how to make Grails extensible and the fruits of that can be seen
with the new plugin system which includes:

• A new Groovy-based build system based on Gant for easy command line
  scripting (http://grails.org/Command+Line+Scripting)

• A new mechanism for the generic encoding and decoding of data
  (http://grails.org/Dynamic+Encoding+Methods)

• The Plugin Development API (http://grails.org/The+Plug-in+Developers+Guide)

• A new simple mechanism for adding methods to any Java or Groovy
  object at runtime (http://grails.org/ExpandoMetaClass)

The plugin system has already been leveraged by early adopters and
there are now XFire and Open Laszlo plugins for Grails
(http://grails.org/Plugins) available. Core parts of grails such as
GORM and taglibs have been refactored into plugins.

During the development of 0.4 we've seen a big increase in usage and
the Grails project has taken on 3 new committers to strengthen the
team (http://grails.org/Who+we+are).
Two new Grails-powered public production sites - the PepsiCo owned
Copella Juice range (http://www.copellafruitjuices.co.uk) and TV
Voting
(http://www.tvvoting.com) - went live and much of the development was
driven by the needs of such projects.

The next release (0.5) will see us focus on further improvements to
GORM, JPA support, JSP Tag lib support and continued improvements to
the core plugin system and any issues that affect day to day Grails
development.

Enjoy!

–
Graeme Rocher
Grails Project Lead
http://grails.org