Web Tools Project/Common/Inventory

org.eclipse.jst.common.annotations.controller 
org.eclipse.jst.common.annotations.core 
org.eclipse.jst.common.annotations.ui

Unclear about the function of these plugins. Is this part of xdoclet support?

org.eclipse.jst.common.frameworks

(internal) Base classes for the flexible project classpath container. This is what the Web App Libraries container is based on.

(internal) org.eclipse.jst.common.jdt.internal.integration Unclear what this is. Contains classes such as JavaArtifactEditModel and WorkingCopyManager.

(public) implementation of the jst.java facet

org.eclipse.wst.common.core

Looks to contain some sort of a search framework. Where is this used?

org.eclipse.wst.common.emf
org.eclipse.wst.common.emfworkbench.integration

EMF integration.

org.eclipse.wst.common.environment

Looks to be some sort of an abstraction for the eclipse log and status reporting.

org.eclipse.wst.common.frameworks
org.eclipse.wst.common.frameworks.ui

The IDataModel/Operation/Wizard framework.

org.eclipse.wst.common.infopop

No code. Appears to contain help content. All of the references in the contexts file are for wst.sse component.

org.eclipse.wst.common.modulecore

The flexible project infrastructure.

org.eclipse.jst.common.project.facet.core
org.eclipse.wst.common.project.facet.core
org.eclipse.wst.common.project.facet.core.tests
org.eclipse.wst.common.project.facet.ui
org.eclipse.wst.common.project.facet.ui.tests

The faceted project framework.

org.eclipse.wst.common.snippets
org.eclipse.wst.common.snippets.tests

Snippets support.

org.eclipse.wst.common.tests
org.eclipse.wst.common.tests.collector
org.eclipse.wst.common.tests.performance
org.eclipse.wst.common.tests.ui

Looks to be some test-related utilities and general test infrastructure. Is some of this actually releng?

org.eclipse.wst.common.ui

Misc UI stuff that didn't belong someplace else.

org.eclipse.wst.common.ui.properties

Tabbed properties view.

org.eclipse.wst.common.uriresolver

What is this and where is it used?

org.eclipse.wst.command.env
org.eclipse.wst.command.env.core
org.eclipse.wst.command.env.ui
org.eclipse.wst.command.env.infopop

Command Framework. Could someone explain what this is?

org.eclipse.wst.validation
org.eclipse.wst.validation.infopop

Validation Framework

org.eclipse.jem.util

can someone explain what this is?

org.eclipse.wst.internet.cache
org.eclipse.wst.internet.cache.tests

What is this? I also noticed that these appear to be in the common project, while other prlugins in the wst.internet namespace (such as wst.internet.monitor and wst.internet.proxy are not).