Varnish

Varnish Cache is a web accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any web server that speaks HTTP and configure it to cache the content. Varnish Cache is very, very fast and will improve your site's loading speed. One of the major merits of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to choose how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory caching system for boosting the load speed of dynamic database-driven websites. 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 system uses a two-tier architecture. The Memcached distributed memory caching system is employed by some of the most traffic-heavy websites on the Internet and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software platform for writing highly scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and efficient, ideal for high-performance data-rich Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source relational database management system. A storage engine is the underlying software component that a database management system uses to create, read, update and delete data from a database. Its latest release features significant improvements in efficiency, security and usability. InnoDB provides the standard ACID database transaction features, as well as foreign key support. It is included as standard in most binary distributions from MySQL AB.