I haven't attempted this, but you can create a local mirror site, from where everyone else can pickup the Eclipse plug-ins.

PS: This method is a bit hackish, but it is based off the site-map reference. This will include the subdirectory on the server where the JAR is available, and also the directory in the Eclipse installation where they need to be placed. Note the url attribute of each JAR that needs to be downloaded.If you are lucky, you'll find the description of the JAR in the category node. This can be determined by the version attribute for each 'feature'. Filter the list of JARs to be downloaded to the version of the plugin that you intend to use.This is normally found in the site.xml file in this case, you'll find it in. Identifying the list of JARs required is the first step. Here's an example of how to do this for the m2eclipse plugin: In certain cases, it is necessary to start Eclipse with a -clean switch. Most Eclipse plug-ins can be installed without the Eclipse updater, by copying the required JARs available at the update site, into the plugins and features directories of the Eclipse installation.

Eclipse git plugin install