• oracleapex.com -> Oracle APEX OTN site
• addon.oracleapex.com -> APEX Lib Developer Addon
• api.oracleapex.com -> API docs
• doc(s).oracleapex.com -> Main document page
• forum(s).oracleapex.com -> OTN APEX forums
• guide.oracleapex.com -> Builders guide
• install.oracleapex.com -> Installation guide
• lang.oracleapex.com -> Used for language specific sites
  • lang.oracleapex.com/deutsch -> German user page
  • lang.oracleapex.com/german -> German user page
• martin.oracleapex.com -> talkapex.com
  • This wasn’t my idea. Tim St. Hilaire requested it so if you have an issue talk to him 😉
• oll.oracleapex.com -> Oracle Learning Library page
• plugin.oracleapex.com -> apex-plugin.com
• urlsyntax.oracleapex.com -> Quick link to the URL syntax document page

http://www.talkapex.com/

Thanks to Martin D’Souza