Currently using WordPress on all web projects I begin or redesign.
WordPress is web software you can use to create a beautiful website, blog, or app. They like to say that WordPress is both free and priceless at the same time.
WordPress is definitely the world's most popular CMS. The script is in its roots more of a blog than a typical CMS. For a while now it's been modernized and it got thousands of plugins, what made it more CMS-like.
The script as an Open Source is the first choice for most bloggers, but it can also be successfully used for designing simple websites.