Proteus - Proteus is a great electrical suite for circuit simulation purposes. You can simulate a single processor or multiple ones at the same time. The application is a great alternative for Virtual System Modelling.
15 Alternatives To Proteus
Drupal - the leading open-source CMS for ambitious digital experiences that reach your audience across multiple channels. Because we all have different needs, Drupal allows you to create a unique space in a world of cookie-cutter solutions.
WordPress is web software you can use to create a beautiful website or blog. We like to say that WordPress is both free and priceless at the same time. Extend WordPress with over 55,000 plugins to help your website meet your needs.