nginx - A high performance free open source web server powering busiest sites on the Internet.
AWS Elastic Load Balancing - Amazon ELB automatically distributes incoming application traffic across multiple Amazon EC2 instances in the cloud.
KEMP Load Balancer - L4/7 Load Balancer w SSL offload
Azure Traffic Manager - Microsoft Azure Traffic Manager allows you to control the distribution of user traffic for service endpoints in different datacenters.
Haproxy - Reliable, High Performance TCP/HTTP Load Balancer
Google Cloud Load Balancing - Google Cloud Load Balancer enables users to scale their applications on Google Compute Engine.