Tempted to go ahead and write your own plugin ? No obligation, but you might want to share it with the Sonar community. In that case hosting your plugin at sonar-plugins.codehaus.org brings you many benefits :

The community helps you more easily, as well as the community benefits from the plugin
Hosting in the Github organization named SonarCommunity
Use JIRA to track issues
Use Atlassian Bamboo for continuous integration
Use this wiki for the documentation
Most of all the plugin is available in Update Center, so users can install the plugin directly from the application

Request Hosting

Create an account at Codehaus
Subscribe to dev@sonar.codehaus.org
Send e-mail to dev@sonar.codehaus.org and tell us your Codehaus ID, so that we can give you a commit access to github. You can request access rights to Nemo too.

Prerequisites

The plugin must support ~~Java 5~~ (Java 6 since March 2013). The Continuous Integration job uses Oracle JDK 6.
The plugin is built with Maven 2.2.x or 3.x.

Principles

When you utilize the forge, we request that you respect the following principles :

Follow Best practices and Sonar Code Style.
The copyright belongs to whoever wrote the plugin
The license must be business friendly
Follow the release process described bellow.

Maven POM

The directory name is the plugin name.
The groupId is 'org.codehaus.sonar-plugins' and artifactId is 'sonar-<name>-plugin'. For example the plugin "foo" is stored in the directory "foo" and its artifact id is "sonar-foo-plugin"

Set the following properties :

<project>
  <parent>
    <groupId>org.codehaus.sonar-plugins</groupId>
    <artifactId>parent</artifactId>
    <!-- 
         The latest version can be found by looking at the tags starting with "parent-" 
         in http://svn.codehaus.org/sonar-plugins/tags/
    -->
    <version>REPLACE_BY_LATEST_VERSION</version>
    <relativePath>../parent</relativePath>
  </parent>
  <artifactId>sonar-foo-plugin</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>sonar-plugin</packaging>
  <name>Plugin name</name>
  <description>Plugin description</description>
  <url>http://docs.codehaus.org/display/SONAR/MY+PLUGIN</url>
  <inceptionYear>2013</inceptionYear>
  <organization>
    <name>My Organization</name>
    <url>http://www.my-organization.com</url>
  </organization>
  <issueManagement>
    <system>JIRA</system>
    <url>http://jira.codehaus.org/browse/SONARPLUGINS/component/MY-COMPONENT-ID</url>
  </issueManagement>
  <scm>
    <connection>scm:svn:http://svn.codehaus.org/sonar-plugins/trunk/MY-PLUGIN</connection>
    <developerConnection>scm:svn:https://svn.codehaus.org/sonar-plugins/trunk/MY-PLUGIN</developerConnection>
    <url>http://svn.sonar-plugins.codehaus.org</url>
  </scm>
  ...
</project>

Configure your pom by overriding values provided by parent - see Sonar Plugins Forge Parent POM. Default license is LGPL3.
Follow Maven POM Code Convention
Add the plugin to the main pom of the forge

Continuous Integration

Please send an email to the dev mailing list in order the plugin to be added to our Continuous Integration server.

How to Release

The release process is explained in this page.