Varnish

Varnish Cache is a web accelerator also called as an HTTP accelerator. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will make your website load much faster. One of the key strengths of Varnish Cache is the flexibility of its configuration language, VCL, which permits you to specify how incoming requests should be tackled.

Memcached

Memcached is a general-purpose distributed memory caching system for boosting the load speed of dynamic database-powered sites. It is used to decrease 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 distributed memory object caching system uses a two-tier architecture. The Memcached system is used by some of the most popular websites on the Internet and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a platform for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, great for high-performance content-intensive Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source 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. The latest release of InnoDB features considerable improvements in efficiency, stability and usability. InnoDB provides the standard ACID transaction properties, as well as referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.