REAPER is a powerful but sensible Windows program that lets you record, edit, render and arrange multi-track waveform audio.
REAPER provides an extensive set of features, but is a very small and lightweight application (the installer is less than 1 megabyte, and includes many effects and a sample project).
Here are some key features of "REAPER":
Supports ASIO, Kernel Streaming, WaveOut, and DirectSound for playback and recording
Reads WAV, OGG, and MP3 files, records WAV files
Lets you arrange any number of items in any number of tracks
Supports audio processing plug-ins (DirectX and Jesusonic)
Volume, pan controls and envelopes per track
Multi-layer undo/redo support
User creatable color themes