Varnish

Varnish Cache is a web application accelerator also popular 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 very, very fast and will improve your site's loading speed. One of the key advantages of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to choose how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory object caching system for increasing the load speed of dynamic database-driven web sites. It is used to decrease 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 distributed memory caching system uses a two-tier architecture. The Memcached memory object caching system is employed by some of the most traffic-heavy websites on the web and is supported by famous web apps 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, non-blocking I/O model that makes it lightweight and efficient, great for high-performance content-rich 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 main software component that a DBMS uses to create, read, update and delete data from a database. Its latest version offers substantial improvements in performance, security and functionality. InnoDB provides the standard ACID database transaction properties, along with declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.