Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will boost the loading speed of your site. One of the chief advantages of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to determine how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory object caching system for increasing the load speed of dynamic database-powered web sites. It is used to lower the number of times an external data source (such as a database or API) is read by caching data and objects in RAM. The Memcached memory object caching system uses a two-tier architecture. The Memcached distributed memory caching system is used by some of the most regularly visited web sites on the web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, great for high-performance data-rich applications. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source database management system. A storage engine is the principal software component that a DBMS uses to create, retrieve, update and delete data from a database. The latest edition of InnoDB features significant improvements in efficacy, security and usability. InnoDB offers the standard ACID database transaction features, along with foreign key support. InnoDB is included by default in most binaries distributed by MySQL AB.