Code Analysis
Cppcheck Portable - C/C++ analysis tool
Database
Database Browser Portable (Freeware) - Manage multiple databases
DB Browser for SQLite Portable - Simple SQLite database management tool
Sqliteman Portable - SQLite databases made easy
Q-Eye Portable (Freeware) - lightweight QlikView data file viewer
Packaging
NSIS Portable - Windows installer and launcher creation
PortableApps.com Installer - the easy way to package portable apps
Portablization
PortableApps.com Launcher - make apps portable without writing code
Programming Environment
SWI-Prolog Portable - Prolog programming environment
Servers
XAMPP - Apache, mySQL, PHP, phpMyAdmin and more in an integrated package
Text Editors & Integrated Development Environments
AkelPad Portable - lightweight plaintext editor
CudaText Portable - Customizable text editor
Frhed Portable - free hex editor
Geany Portable - Text editor and basic IDE
gVim Portable - advanced, feature-rich text editor
HM NIS Edit Portable - NSIS development environment
Notepad++ Portable - A full-featured text editor with syntax highlighting
Notepad2 Portable - Simple, lightweight text editor
Notepad2-mod Portable - Lightweight text editor
Translation
IniTranslator Portable - INI translation tool
Web Editors
KompoZer Portable (formerly Nvu) - The easy-to-use web editor