Varnish

Varnish Cache is a web accelerator also referred to as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is very, very fast and will improve the loading speed of your site. One of the important pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to choose how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory caching system for boosting the speed of dynamic database-driven web sites. It is used to reduce 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 caching system uses a client/server architecture. The Memcached memory object caching system is used by some of the most frequently visited sites on the World Wide Web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software platform for writing scalable Internet apps. Written in JavaScript, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, great for real-time content-heavy Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source DBMS. A database engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest release features considerable improvements in performance, reliability and usability. InnoDB provides the standard ACID-compliant database transaction properties, along with declarative referential integrity support. It is included by default in most binaries distributed by MySQL AB.