Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is really, really fast and will speed up your site. One of the chief strengths of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to define how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory caching system for boosting the load speed of dynamic database-driven websites. It is used to lower the number of times an external data source (such as a DB or API) is read by caching data and objects in RAM. The Memcached distributed memory object caching system uses a client'server architecture. The Memcached system is used by some of the most regularly visited sites on the web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software platform for writing highly scalable Internet applications. Written in JavaScript, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, suitable for real-time data-heavy network applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source database management system. A database engine is the underlying software component that a DBMS uses to create, read, modify and delete data from a database. Its latest edition offers substantial improvements in performance, stability and functionality. InnoDB offers the standard ACID database transaction attributes, along with referential integrity support. It is included by default in most binaries distributed by MySQL AB.