Script DB - A scripting addition that gives AppleScript built-in database commands, such as insert, delete, sort and find records. Supports FileMaker Pro. - http://www.applescriptdb.com/
ACME Script Widgets - Scripting additions for text and list manipulations. Also helps with cgi scripts. - http://www.acmetech.com/products/asw/acme-script-widgets.html
FindFile OSAX - Scripting addition lets users search for files within scripts. - http://microcosmsoftware.com/findfileosax/index.html
Appearance OSAX - Scripting addition featuring display alert, post notification & more soon - 46k - http://www.24usoftware.com/AppearanceOSAX
Application Menu - Scripting addition that automates access to the Application menu - http://www.geek-central.gen.nz/sw/index.html
Tanaka's osax - Scripting addition for manipulations of Japanese texts, and cgi scripts. - http://mtlab.ecn.fpu.ac.jp/tanaka_osax.html
Jon's Commands - Scripting addition with over 30 commands. - http://www.seanet.com/~jonpugh/JonsCommandsDocs.html
SmartWrap - Scripting addition that wraps text. - http://www.selznick.com/products/smartwrap/mac.htm
Stuffit Commands - Scripting addition to stuff and unstuff files. - http://www.lazerware.com/software.html
XML Tools - Scripting addition that parses and generates XML. - http://www.latenightsw.com/freeware/XMLTools2/index.html
Scripting Additions Database - Extensive database of information about Scripting Additions (osaxen) for AppleScript. - http://www.osaxen.com/
Prefab Software - Developer of PreFab Player, an extension that allows AppleScript to control user interface, and Text Machine, an application that gives AppleScript advanced text editing tools. - http://www.prefab.com
AppleScript Formatting - Scripting addition to get and set AppleScript formatting styles. - http://www.merzwaren.com/snippets/index.html