Web Application is a type of application, which is based on web browser and uses it as a client. This term may also mean that such applications are coded in a browser-supported programming language and reliant on a common web browser to render the application executable.

Web applications are popular due to the ubiquity of web browsers, and the convenience of using a web browser as a client, sometimes called a thin client. The ability to update and maintain web applications without distributing and installing software on potentially thousands of client computers is a key reason for their popularity, as is the inherent support for cross-platform compatibility. Common web applications include webmail, online retail sales, online auctions, wikis and many other functions.

Web application development is the process and practice of developing web applications.

As well as desktop applications, web applications have fluctuating level of risk. Preventing the risks include concern, documentation, test planning, change control, requirements analysis, architectural description and formal design and construction practices. 

OLSOFT develops web applications under: Ajax, ASP, ASP.NET, CSS, JavaScript, Perl, PHP, Ruby, including Ruby on Rails, Python, Django and HTML5.