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Site Info - System21.tv
Overview of web technologies used by System21.tv.
System 21 — Обучающая платформа Системы21
automatic translation provided by Microsoft
System 21-learning platform Sistemy21
Description on Homepage
Number 1,572,824 of all websites according to Alexa
WordPress is an open source blog publishing and content management system, based on PHP and MySQL.
PHP is a popular scripting language for creating web pages.
HTML5 is the fifth revision of the HTML standard.
UTF-8 (8-bit Unicode Transformation Format) is a variable-length character encoding for Unicode, which is backwards compatible with ASCII.
PNG (Portable Network Graphics) is a lossless compression image format, suitable to store graphics with uniformly colored areas, and originally introduced as a free, open-source successor of GIF.
JPEG (Joint Photographic Experts Group) is a lossy compression method suitable to store photographic images.
Scalable Vector Graphics (SVG) is an XML-based vector image format.
External Cascading Style Sheets define style rules in a separate CSS file.
Embedded Cascading Style Sheets define a set of style rules in a <style> element within a web page.
Inline Cascading Style Sheets define style rules directly within an (X)HTML element using the style attribute.
Gzip (GNU zip) is a file compression algorithm.
HTTP/2 is the second major version of the HTTP network protocol.
Session cookies are temporary cookies, which are deleted when the user closes the browser.
Persistent cookies with an expiration time between 1 day and 1 month.
Non-HttpOnly cookies are used in the HTTP protocol and also in client side scripts, which may be a security threat.
Non-secure cookies may be used via an unencrypted connections, which may be a security threat.
A weak ETag is an HTTP header field for validation of cached web pages, that indicates a semantically equivalent page in the cache.
The websites redirects visitors to its www subdomain, e.g. from example.com to www.example.com.
Generic RDFa (Resource Description Framework in attributes) is RDFa without further specialization.
The Open Graph protocol, originally developed by Facebook, is an RDFa-based format that enables any web page to become a rich object in a social graph.
IdenTrust is a SSL certificate authority.
The SSL certificate is invalid because it is not issued for the domain where it is used.
Google Analytics is a free service to get detailed statistics about the visitors of a website, provided by Google.
Nginx (pronounced as "engine X") is a lightweight open source web server developed by Igor Sysoev.
The Apache HTTP Server is a popular open source web server by the Apache Software Foundation.
HostGator is a web hosting provider owned by Endurance.
Weebly is a hosted website building service.
Tuvalu, also used for television related sites
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