If you can't connect to the internet from your JDeveloper, you can directly download JDeveloper extensions from the update centers, and point the "help->check for update" to the file you have downloaded. Available update centers:

• Official Oracle Extensions Update Center
• Partners and Open Source Extensions Update Center

You can find a list of extensions for previous versions here.

Oracle provides an extension development kit with samples and documentation to help you build your own extensions.

We invite you to contribute to this exchange by sharing your own JDeveloper extensions. Please post an entry on the discussion forum if you'd like to upload your extension on this page.