Dreamweaver is a HTML editor and web development application created by Macromedia and now developed by Adobe Systems. It is available for both Mac and Windows and supports technologies like CSS, JavaScript, ASP, ColdFusion, and PHP. Dreamweaver allows users to preview websites locally and edit HTML files locally before uploading them to remote servers via FTP, SFTP, or WebDAV. It also supports syntax highlighting to easily edit scripts in languages like HTML, XML, JavaScript, ASP, and C#.