There are many open source tools for Web development such as BerkeleyDB, GlassFish, LAMP (Linux, Apache, MySQL, PHP) stack and Perl/Plack. This has kept the cost of learning Web development to a minimum. Another contributing factor to the growth of the industry has been the rise of easy-to-use WYSIWYG Web-development software, such as Adobe Dreamweaver, BlueGriffon and Microsoft Visual Studio. Knowledge of HyperText Markup Language (HTML) or of programming languages is still required to use such software, but the basics can be learned and implemented quickly. An ever-growing set of tools and technologies have helped developers build more dynamic and interactive Web sites. Further, Web developers now help to deliver applications as Web services which were traditionally only available as applications on a desk-based computer. This has allowed for many opportunities to decentralize information and media distribution. Examples can be seen with the rise of cloud services such as Adobe Creative Cloud, Dropbox and Google Drive. These Web services allow users to interact with applications from many locations, instead of being tied to a specific workstation for their application environment. Examples of dramatic transformation in communication and commerce led by Web development include e-commerce. Online auction sites such as eBay have changed the way consumers find and purchase goods and services. Online retailers such as Amazon.com and Buy.com (among many others) have transformed the shopping and bargain-hunting experience for many consumers. Another example of transformative communication led by Web development is the blog. Web applications such as WordPress and Movable Type have created blog-environments for individual Web sites. The increased usage of open-source content management systems and enterprise content management systems has extended Web development's impact at online interaction and communication. Web development has also impacted personal networking and marketing. Web sites are no longer simply tools for work or for commerce, but serve more broadly for communication and social networking. Web sites such as Facebook and Twitter provide users with a platform to communicate and organizations with a more personal and interactive way to engage the public.