Plesk

Plesk is a commercial web hosting and server data center automation software with a control panel developed for Linux and Windows-based retail hosting service providers. Plesk's user management model is suitable for dedicated and shared hosting, allowing server administrators to set up new websites, reseller accounts, email accounts, and edit and create DNS entries through a web-based interface. Key features and solutions include the automation and management of domain names, email accounts, web applications, programming languages, databases, and infrastructure tasks to provide a ready-to-code environment and strong security across all layers and operating systems.
It is developed by Plesk International GmbH, with headquarters in Toronto, Canada and Schaffhausen, Switzerland, and offices in Barcelona, Spain, Cologne, Germany, Tokyo, Japan, and in the Siberian city of Novosibirsk, Russia, where it was originally developed in 2000. 
The hosting automation software was initially released by Plesk Inc. and first went live in 2001. In 2003, Plesk was sold to SWSoft, which became Parallels in 2008. In March 2015, Parallels renamed the service provider division to Odin. In December of the same year, Plesk became a separate business entity. And in 2017, Plesk was acquired by British Oakley Capital Limited and has since been a part of WebPros, a global SaaS platform for server management. Currently, WebPros comprises Plesk, cPanel, WHMCS, XOVI, and SolusVM.
Overview.
Plesk was founded in 2000 by Dimitri Simonenko when Rackspace became Plesk's first customer. Two decades after its first release, Plesk software operates on more than 370,000+ servers globally, supporting the operations of more than 12 million websites and 15 million email boxes for customers in 230 countries. One of Plesk’s leading extensions, the popular WordPress Toolkit, is live on over 4.6 million instances, and a further 161 extensions are available on the Plesk catalog. 
In October 2018, Plesk integrated support for various Content Management Systems including WordPress and Joomla, and other web software such as git and Docker, as well as framework ready environment for Node.js, PHP, Python, Ruby on Rails, and more. The current version of Plesk (Obsidian 18.x) for Linux supports multiple POSIX platforms, including Debian 9 and 10, Ubuntu 20.04 Server LTS, CentOS 7 and 8, RedHat Enterprise Linux 7 and 8, and CloudLinux 7. And for Windows, Windows Server 2016 and Windows Server 2019 operating systems.
Plesk supports the most popular database engines and is shipped with corresponding database management tools. Plesk for Linux supports MySQL, PostgreSQL, and MariaDB database servers. Plesk for Windows supports Microsoft SQL and MySQL.
The Plesk Platform includes extensions for Backup, DNS, Cloud, Security, and Server Tools. And its control panel allows its users to set up new websites, reseller accounts, email accounts, edit and create DNS entries, and many more, through a web-based interface. 
Today, Plesk is used and offered by thousands of Hosting companies and Cloud Service Providers worldwide – including top players like GoDaddy, 1&1, Media Temple, AWS, Google, Microsoft Azure, DigitalOcean, Vultr, and many more.
Plesk’s web-server management tools secure and automate server and website administration as well as operations to free up time and allow developers, designers, and agencies to focus on their core businesses.
Licenses.
Plesk, with latest version Obsidian 18.x, is available in the following license configurations:
The license price also distinguishes whether a license can be used for a dedicated server or a virtualized server. Licenses for dedicated servers are usually slightly more expensive.
Pricing.
Plesk sells all three licenses for a monthly or annual price directly. All three editions can also be obtained from official license resellers.
In March 2018, Plesk announced end-of-life versions price increase, becoming its first price adjustment in 18 years of business. The company raised the prices of all Plesk licenses that had versions earlier than 12, alleging it was to cover the increasing cost of support and management over the past two decades. Following the announcement, Plesk created a FAQ page to clarify any questions about the new pricing adjustment.
Support.
Live and email support for Plesk is available in English, Russian, Spanish, German, Portuguese, and Japanese. Plesk licenses purchased directly from Plesk include full free support.
If a Plesk license is purchased from one of the Plesk partners, technical support is the corresponding partner's responsibility. Plesk partners are fully trained and deliver best-in-the-industry support for Plesk products running on their infrastructure. For those who wish to access Plesk support despite having bought the license from another source than the Plesk online store, Plesk support subscriptions are also available for purchase.
Plesk University.
In January 2016, Plesk launched Plesk University online. Through its University, Plesk provides a full range of courses to help users learn how to use their products and services. All courses and exams in their catalog are certified, and access to all of them is free.