几个国外的开源社区

sourceforge http://www.sourceforge.net/
codeproject http://www.codeproject.com/
opensource http://www.opensource.org/
java.net http://www.java.net/

Lomboz http://www.objectlearn.com/index.jsp(J2EE plugin for Eclipse)
htmlArea http://sourceforge.net/projects/itools-htmlarea/(所见即所得的在线HTML编辑器)
XmlBuddy http://www.xmlbuddy.com/(XML Editor plugin for Eclipse)
JFreeChart http://www.jfree.org/(用于生成图表的项目)
EclipseMEhttp://eclipseme.sourceforge.net/(J2ME Developmnt Plugin for Eclipse)
mvnForum http://sourceforge.net/projects/mvnforum/(论坛)
jChatBox http://www.javazoom.net/index.shtml(用servlet实现的WEB聊天引擎)
POI http://jakarta.apache.org/poi/index.html(用于处理Excel,WORD等文档的项目)
FileUpload http://jakarta.apache.org/commons/fileupload/(用于处理HTTP文件上传得项目)
PDFBox http://sourceforge.net/projects/pdfbox/(处理PDF文档的项目)
Lucene http://jakarta.apache.org/lucene/index.html(搜索引擎)
Digester http://jakarta.apache.org/commons/digester/(处理XML信息的项目)
DBCP http://jakarta.apache.org/commons/dbcp/ (数据库连接池)
AXIS http://ws.apache.org/axis/(WebService 的实现框架)
Jetspeed http://portals.apache.org/jetspeed-1/(Portal)
HSQLDB http://sourceforge.net/projects/hsqldb/(Im memory Database Engine)
CEWOLF http://sourceforge.net/projects/cewolf/ (一套标签库实现Web报表,使用的是jFreeChart引擎)
Struts Menu http://sourceforge.net/projects/struts-menu/ (基于Struts的Web菜单项目)
htmlparser http://sourceforge.net/projects/htmlparser/ (用于解析HTML信息的项目)
Mondrian http://sourceforge.net/projects/mondrian/ (Open Source OLAP Database)
ProGuard http://sourceforge.net/projects/proguard/(Java的混淆器)
InfoGlue http://sourceforge.net/projects/infoglue/ (J2EE 内容管理系统)
JPivot http://sourceforge.net/projects/jpivot/ (基于WEB的OLAP 展现)
http://java-source.net/

http://www.codeplex.com/