See 
PublishedAPI for packages intended to be used by Plugin and Contrib authors, or 
browse all packages.
See also 
Developing plugins, 
Developer's Bible, 
Technical Overview
  internal package Foswiki::Compatibility  
Support for compatibility with old versions. Packaged
separately because 99.999999% of the time this won't be needed.
 StaticMethod upgradeCategoryTable( $session, $web, $topic, $meta, $text ) → $text 
Upgrade old style category table
May throw 
Foswiki::OopsException
 migrateToFileAttachmentMacro ( $session, $meta, $text  ) → $text 
Migrate old HTML format
 upgradeFrom1v0beta ( $session, $meta  ) → $text