RoadRunner is an open source (MIT licensed), high-performance PSR-7 PHP application server, load balancer and process manager. It supports service model with ability to extend it's functionality on a project basis.

Cilium is open source software for providing and transparently securing network connectivity and loadbalancing between application workloads such as application containers or processes. Cilium operates at Layer 3/4 to provide traditional networking and security services as well as Layer 7 to protect and secure use of modern application protocols such as HTTP, gRPC and Kafka. Cilium is integrated into common orchestration frameworks such as Kubernetes and Mesos.

PPM is a process manager, supercharger and load balancer for PHP applications.
It's based on ReactPHP and works best with applications that use request-response frameworks like Symfony's HTTPKernel. The approach of this is to kill the expensive bootstrap of PHP (declaring symbols, loading/parsing files) and the bootstrap of feature-rich frameworks. See Performance section for a quick hint. PHP-PM basically spawns several PHP instances as worker bootstraping your application (eg. the whole Symfony Kernel) and hold it in the memory to be prepared for every incoming request: This is why PHP-PM makes your application so fast.

Træfɪk is a modern HTTP reverse proxy and load balancer made to deploy microservices with ease. It supports several backends (Docker, Swarm, Mesos/Marathon, Kubernetes, Consul, Etcd, Zookeeper, BoltDB, Rest API, file…) to manage its configuration automatically and dynamically.

Rancher is open source software that makes it simple for organizations to deploy a private container service and deliver Docker orchestration to users. Within a team, authorized users are able to create resource pools from any hosts, and then launch containers or application templates from Rancher’s UI or CLI. Users have complete control over how their applications are deployed, and Rancher provides all of the necessary infrastructure services such as networking, load balancing, and storage to ensure the application runs brilliantly on any infrastructure.