Adventure Kid has released AKWF Waveforms, a free collection of single cycle waveform samples.
I have been making and collecting one cycle waveforms for years. They have been one of my best weapons to use when making sounds. If you have a wavetable synthesizer that can load single cycle waveforms you might find them useful as well.
If you are familiar with basic subtractive synthesizers you probably know the saw, square, sinus and triangle shape that are the most common shapes a oscillator can produce pretty well. Single cycle waveforms are tiny audio files (.wave) that a synthesizer can read to use as oscillator shapes. What it means is new sounds. Some kind of grey area between sampling and synthesis. A raw waveform is very rarely what makes a whole sound but you can see it as presets for oscillators. Happy sound designing!
This kind of technique is also called Wavetable synthesis if the oscillator switches waveform.
The AKWF Waveforms collection is available as a free download (Creative Commons Attribution 3.0 Unported License).
More information: Adventure Kid