Varnish

Varnish Cache is a web accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is very, very fast and will increase your site's loading speed. One of the main features of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to determine how incoming requests should be dealt with.

Memcached

Memcached is a generic memory caching system for boosting the load speed of dynamic database-driven web sites. It is used to reduce 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 memory caching system uses a client'server architecture. The Memcached distributed memory object caching system is employed by some of the most traffic-intensive sites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and effective, excellent for real-time content-heavy apps. 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 relational database management system. A storage engine is the primary software component that a database management system uses to create, retrieve, modify and delete data from a database. The latest edition of InnoDB offers considerable improvements in efficacy, stability and usability. InnoDB offers the standard ACID transaction features, along with declarative referential integrity support. It is included as standard in most binary distributions from MySQL AB.