With the amount of users on the web steadily increasing websites must at times endure heavy loads and risk grinding to a halt beneath the flood of visitors. One solution to this problem is by using HTTP reverse proxy caching, which acts as an intermediate between web application and user. Content from the application is stored and passed on, avoiding the need for the application produce it anew for every request. One popular application designed solely for this task is Varnish; another interesting application for the task is Nginx which is primarily designed as a web server. This thesis compares the performance of the two applications in terms of number of requests served in relation to response time, as well as system load and free memory. With both applications using their default configuration, the experiments find that Nginx performs better in the majority of tests performed. The difference is however very slightly in tests with low request rate.