Varnish

Varnish Cache is a web accelerator also called as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is really, really fast and will improve your site's loading speed. One of the key strengths of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to specify how incoming requests should be dealt with.

Memcached

Memcached is a generic memory object caching system for speeding up dynamic database-powered websites. 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 object caching system is used by some of the most regularly visited web sites on the web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and effective, perfect for real-time data-intensive 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 relational database management system. A storage engine is the primary software component that a database management system uses to create, read, modify and delete data from a database. Its latest version offers serious improvements in efficiency, dependability and usability. InnoDB provides the standard ACID database transaction attributes, along with referential integrity support. It is included by default in most binaries distributed by MySQL AB.