Weft MaybeUpload Servlet
- A package intended to ease the creation of upload servlets (BSD-style license).
- http://www.weft.co.uk/library/maybeupload/

CoolServlets.com
- Free, open source Java servlets. Guestbooks, csmailform, postcards and email packages.
- http://www.coolservlets.com/

GifServlet
- GifServlet is a base class enabling you to generate GIF images from a servlet.
- http://www.javasource.org/GifServlet/

Melati
- An application development toolkit built on top of Java servlet technology.
- http://melati.org/

Web Progressor
- A server-side component for easy creation and manipulation of client-side progress bars.
- http://www.sunwesttek.com/wp/jsp/

Gomba
- A collection of Java servlets that allow developers to quickly build REST-style web services that expose data accessed via the JDBC API to the Web. [Open Source, Apache license 2.0]
- http://gomba.sourceforge.net/

JetSpeed
- Servlet implementation of an open protocol GroupWare product. The backend (search engines, news, weather, POP3/IMAP/LDAP/NNTP, database) will be based on other open source packages. [Open Source, BSD-like]
- http://portals.apache.org/jetspeed-1/

JERSS
- Integrate RSS newsfeeds into a Web site with control over presentation.
- http://www.jayeckles.com/news/

JFormMail
- A generic HTML form to e-mail gateway that parses the results of any form and sends them to the specified users. It 100% compatible with Matt's original FormMail script. [Open source]
- http://jformmail.sourceforge.net/

JUpload
- Uploading file servlet, includes demo.
- http://www.vixa.com/jupload/