Varnish

Varnish Cache is a web accelerator also famous as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will boost the speed of your web site. One of the essential virtues of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for boosting the loading speed of dynamic database-driven 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 caching system uses a client/server architecture. The Memcached system is employed by some of the most traffic-hungry web sites on the World Wide Web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for writing scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and effective, ideal for real-time content-rich applications. 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 DBMS. A storage engine is the underlying software component that a database management system uses to create, retrieve, modify and delete data from a database. Its latest release features serious improvements in efficiency, stability and functionality. InnoDB provides the standard ACID-compliant database transaction features, as well as declarative referential integrity support. It is included by default in most binary distributions from MySQL AB.