44. Packt Publishing Open Source AwardsThis book and e-book publisher also awards annual prizes for outstanding open source software. Most of the winners and runners up on this list would be of interest to Web developers.
45. Top 100 Network Security Tools
Insecure.org created this list in 2006 based on a survey of people who received an Nmap newsletter. It provides a good overview of some of the more mature security (and hacking) tools.
46. OSSwin
The OSSwin project provides a directory of open source software that runs on Windows. It's a little bit dated, but it can help you find some "oldies but goodies."
47. Top 100 of the Best (Useful) OpenSource Applications
This list on the UbuntuLinuxHelp blog offers a good overview of useful apps for Linux users. It's a couple of years old, but most of the links are still good.
48. Open Source FreewareThis site is also a few years old, but has an interesting way of listing the applications it contains. It describes each app by its primary feature, for example, after "I want to protect the computer against viruses" it lists ClamWin.
49. Open Source God
This list from Mashable.com is impressive for its length and breadth. It includes more than 480 great open source applications from a very wide variety of categories.
This page offers short, simple descriptions of some of the most well-known open source apps for Windows, with links to each.
51. Open Source Mac
A slightly longer list that follows the same format as "Open Source Windows"—only highlighting open source apps that work on OS X.
52. Wikipedia
The free and open source community has contributed heavily to the free encyclopedia, and as a result, Wikipedia has a wealth of articles with good information on open source software. The link above has an extensive list of open source projects with articles on Wikipedia. From these articles, you can usually link to the project site or a download page.
53. Koders
This Black Duck-sponsored site allows users to search a database of open source code. It claims 30,000 users per day and more than 3 billion lines of code in its database.
54. Melquiades
Melquiades provides an interface to the data collected and analyzed by the FLOSSMetrics project. The FLOSSMetrics Project is a European Commission-funded project to build a database of information about open source projects, particularly those of interest to small and medium-sized enterprises.
55. Apache Software Foundation
The Apache Software Foundation currently sponsors nearly 100 enterprise-grade open source projects listed on this site. Many Apache projects, including the well-known HTTP Server, relate to Web-based technologies.
56. KDE
In addition to the well-known desktop environment for Linux, the KDE community has created many different types of applications, many of which run on multiple platforms. The link here will take you to the big list of KDE applications.
57. Xiph
The Xiph Foundation describes itself as "a non-profit corporation dedicated to protecting the foundations of Internet multimedia from control by private interests." With that goal in mind, the group has developed a number of open source multimedia tools, including several open audio and video codecs.
58. W3C
The World Wide Web Consortium, also known as "W3C," is primarily known as a developer of Web standards. However, the group has also created a number of open source tools for Web developers.
59. NASA
The space agency has released the code for a number of pieces of software its engineers have created. Not surprisingly, several are related to science and space exploration, but many others would be of interest to IT managers or educators.