Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any web server that speaks the HTTP protocol 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 enables you to choose how incoming requests should be tackled.

Memcached

Memcached is a generic memory caching system for boosting the loading speed of dynamic database-driven web sites. It is used to reduce the number of times an external data source (such as a DB or API) is read by caching data and objects in RAM. The Memcached system uses a two-tier architecture. The Memcached distributed memory object caching system is employed by some of the most regularly visited websites on the web and is supported by famous Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and efficient, great for high-performance content-heavy Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built 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 DBMS uses to create, retrieve, modify and delete data from a database. The latest version of InnoDB features substantial improvements in efficacy, stability and functionality. InnoDB provides the standard ACID-compliant transaction features, as well as foreign key support. It is included by default in most binaries distributed by MySQL AB.