Nginx, pronounced “Engine X”, is a rocketed high-performance Web server and reverse proxy on last 3 years. It was created by Igor Sysoev for, Russia's second-largest Web site. Nginx is able to serve more requests per second with less resources because of its architecture. It consists of a master process, which delegates work to one or more worker processes. Each worker handles multiple requests in an event-driven or asynchronous manner using special functionality from the Linux kernel (epoll/select/poll).

Nginx has become very popular these days, since a wordpress and youporn use it, many web server attend to use Nginx with reason of usability and speed/high Performance. Here are some Fact of Nginx and thats why
Ngix ? collected by our team mates:

Introduction :
Apache is the most popular Web server and one of the most successful open-source projects of all time. Since April 1996, Apache has served more Web sites than any other Web server. Many of the world's largest Web sites, including YouTube, Facebook, Wikipedia and Craigslist, use Apache to serve billions of page views per month. Over the years, Apache has proven itself to be a very stable, secure and configurable Web server. Although Apache is an excellent Web server, what if there were an alternative with the same functionality, a simpler configuration and better performance? That Web server exists, and it's called Nginx.

Nginx Features :
Like Apache, Nginx has all the features you would expect from a leading Web server:

  • Static file serving.
  • SSL/TLS support.
  • Virtual hosts.
  • Reverse proxying.
  • Load balancing.
  • Compression.
  • Access controls.
  • URL rewriting.
  • Custom logging.
  • Server-side includes.
  • WebDAV.
  • FLV streaming.
  • FastCGI.

Between Ngix and Apache
nginx is noted to be a good server for sites that need fast, efficient reverse proxies or fast, efficient serving of static content. It is acclaimed for having low memory usage and is recommended for sites running on a VPS. Apache is like Microsoft Word, it has a million options but you only need six. Nginx does those six things, and it does five of them 50 times faster than Apache. source

Between Lighttpd and Nignx
Nginx and Lighttpd are probably the two best-known asynchronous servers and Apache is undoubtedly the best known process-based server. The main advantage of the asynchronous approach is scalability. In a process-based server, each simultaneous connection requires a thread which incurs significant overhead. An asynchronous server, on the other hand, is event-driven and handles requests in a single (or at least, very few) threads. Pulling numbers from thin air for illustrative purposes, serving 10,000 simultaneous connections would probably only cause Nginx to use a few megabytes of RAM whereas Apache would probably consume hundreds of megabytes (if it could do it at all). source

Nginx Popularity
Accourding to the netcraft survey here, 7.35% of webserver in the world has running Nginx in field of Market Share for Top Servers Across All Domains August 1995 - May 2011. And 8.82% for Totals for Active Servers Across All Domains June 2000 - May 2011, this result is fair enough remember Nginx.

Does Nginx available and support in Ubuntu ?
yes ofcourse, nginx can be installed on ubuntu server using default ubuntu repository. Open Ubuntu Software Center and you will find Nginx it there.