Microsoft WebMatrix 3 is a powerful yet lightweight web development tool.
The program offers code completion, database management (SQL Server, SQL CE, MySQL), and can download and set up a host of free and open source tools: WordPress, DotNetNuke, Drupal, SugarCRM, phpBB, Tiki Wiki, Joomla! and many more.
Bundled iPhone, Windows Phone and iPad simulators help to ensure your sites work on mobile devices. There are tools to help you optimise and tune sites for the best possible performance, and FTP and web deployment options will get your work online.
WebMatrix 3 improves the situation further with good Windows Azure integration; you can sign in with your Microsoft account, then create and host 10 sites for free.
There's now source control, too, courtesy of Git. And while this can normally be a difficult task (for beginners, at least), WebMatrix provides a straightforward front end for the usual command line complexities.
Enhanced remote editing further simplifies the development process. No need to work from a local source, just edit the remote files and your changes are automatically pushed to the site.
And Microsoft says WebMatrix includes "hundreds" of further improvements, "including an extension for PHP validation and Typescript support."