HAProxy

HAProxy, which stands for High Availability Proxy, is a popular open-source software TCP/HTTP Load Balancer and proxying solution that can be run on Linux, macOS, and FreeBSD. Its most common use is to improve the performance and reliability of a server environment by distributing the workload across multiple servers (e.g. web, application, database). It is used in many high-profile environments, including GitHub, Imgur, Instagram, and Twitter.