With Gliffy.com you have an online diagram software that allows you to create technical drawings, diagrams, among other things.

The front page of the site has a picture that shows you how the software looks: you have a column on the left with some basic shapes and with access to libraries and other options, and in the rest of the screen you have your work space.

The software allows you to save your work online, with your own account on the site, or in your computer as an image file. In addition, it has an excellent option to add your diagrams on blogs, sites, and so on.

Url of the site: Gliffy.com