CookielessSessionID by: Allan Thraen

An alternative to the ASP.NET SessionIDManager - this one will let you use session state without setting a cookie.

QRCode by: Allan Thraen

An edit-mode plugin that lets you generate QRCodes.

OutputFormatProvider by: Allan Thraen

A pluggable way to allow different outputformats for each page. For instance, use it to get a page in XML, JSON, PDF or JPG by putting the query-line parameter "outputformat=PDF" on your urls.