If you're on Linux - there's KiCAD, and if you are masochistic, gEDA (it has a very steep learning curve); you can also run EagleCAD on Linux too. There's also this tool: http://www.digikey.com/us/en/mkt/scheme-it.html
If you're on Linux - there's KiCAD, and if you are masochistic, gEDA (it has a very steep learning curve); you can also run EagleCAD on Linux too. There's also this tool: http://www.digikey.com/us/en/mkt/scheme-it.html