Naturally Fritzing cannot be compared to other commercial products like Eagle but it represents a fast and simple way to quickly realize prototypes through the milling process (Gerber export is available) or using a breadboard.
The software, multilanguage, is available for the main operative systems, 32 or 64 bits and can be downloaded here.
The included library has enough included components to realize simple projects. Interesting is the presence of boards very propular as Arduino.