Audacity is a free, easy-to-use and multilingual audio editor and recorder for Windows, Mac OS X, GNU/Linux and other operating systems. You can use Audacity to:
Sumatra PDF is a free PDF, eBook (ePub, Mobi), XPS, DjVu, CHM, Comic Book (CBZ and CBR) reader for Windows. Sumatra PDF is small, portable and starts up very fast. Simplicity of the user interface has a high priority.
Vim is a highly configurable text editor built to enable efficient text editing. It is an improved version of the vi editor distributed with most UNIX systems. Vim is often called a "programmer's editor," and so useful for programming that many consider it an entire IDE. It's not just for programmers, though. Vim is perfect for all kinds of text editing, from composing email to editing configuration files.
SciTE is a SCIntilla based Text Editor. Originally built to demonstrate Scintilla, it has grown to be a generally useful editor with facilities for building and running programs. It is best used for jobs with simple configurations - I use it for building test and demonstration programs as well as SciTE and Scintilla, themselves.
Notepad++ is a free source code editor and Notepad replacement that supports several languages. Running in the MS Windows environment, its use is governed by GPL License. Based on the powerful editing component Scintilla, Notepad++ is written in C++ and uses pure Win32 API and STL which ensures a higher execution speed and smaller program size.