PortableApps.com allows you to carry your favorite computer programs and all of your bookmarks, settings, email and more with you on a portable device (USB flash drive, iPod, portable hard drive, CD, etc) and use them on any Windows computer.
GnuWin provides Win32-versions of GNU tools, or tools with a similar open source licence. The ports are native ports, that is they rely only on libraries provided with any 32-bits MS-Windows operating system, such as MS-Windows 95 / 98 / 2000 / NT / XP /
A mind mapper, and at the same time an easy-to-operate hierarchical editor with strong emphasis on folding. These two are not really two different things, just two different descriptions of a single application. Often used for knowledge and content mgmt.
KeePass Password Safe is a free, open source, light-weight and easy-to-use password manager for Windows. You can store your passwords in a highly-encrypted database, which is locked with one master password or key file.
FMA is a SMS Manager, Mobile Phone Monitor, Remote Control Agent, Phonebook Manager, Organizer, Fun and much more; whatever you want it to be, it is whatever a mobile phone should have :-) (Currently based on Sony Ericsson features set).
GanttProject is a project scheduling application written in Java and featuring gantt chart, resource management, calendaring, import/export (MS Project, HTML, PDF, spreadsheets). Learn more on http://ganttproject.biz
Liferay Portal is the world's leading enterprise open source portal framework, offering integrated Web publishing and content management, an enterprise service bus and service-oriented architecture, and compatibility with all major IT infrastructures.
Nagios is a powerful, enterprise-class host, service, application, and network monitoring program. Designed to be fast, flexible, and rock-solid stable. Nagios runs on *NIX hosts and can monitor Windows, Linux/Unix/BSD, Netware, and network devices.