Websites using some form of Captcha technology on them.
nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
Ubuntu Linux operating system
Google Apps is a cloud-based productivity suite that helps you and your team connect and get work done from anywhere on any device. It's simple to setup, use and manage, allowing you to work smarter and focus on what really matters.
The DOCTYPE is a required preamble for HTML5 websites.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.
The http-equiv attribute provides an HTTP header for the information/value of the content attribute.
The http-equiv attribute can be used to simulate an HTTP response header.
By adding rel="home" to a hyperlink, a page indicates that the destination of that hyperlink is the homepage of the site in which the current page appears.
These websites are related to openjudge.cn in terms of content, traffic and structure