Varnish

Varnish Cache is a web application accelerator also popular 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 boost your website's loading speed. One of the chief pluses of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to define how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose distributed memory caching system for boosting the load speed of dynamic database-powered 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 client/server architecture. The Memcached memory object caching system is employed by some of the most traffic-hungry websites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software system 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 content-heavy Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source DBMS. A database engine is the main software component that a database management system uses to create, retrieve, update and delete data from a database. Its latest release offers significant improvements in efficacy, stability and usability. InnoDB provides the standard ACID-compliant database transaction properties, along with foreign key support. It is included by default in most binary distributions from MySQL AB.