Varnish

Varnish Cache is a web application accelerator also known 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 content. Varnish Cache is really, really fast and will increase your site's loading speed. One of the important attributes of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to determine how incoming requests should be dealt with.

Memcached

Memcached is a generic distributed memory object caching system for increasing the loading speed of 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 caching system uses a two-tier architecture. The Memcached distributed memory object caching system is used by some of the most frequently visited web sites on the 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 applications. Written in JavaScript, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and effective, great for high-performance data-intensive apps. 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 underlying software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest release features substantial improvements in performance, security and functionality. InnoDB provides the standard ACID-compliant transaction properties, as well as referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.