E-mail was one of the first applications on the Internet, and its benefits quickly become clear: fast and convenient transmission (nearly free of charge), the ability to send (or forward) the same information to multiple people with marginal effort, and much more make e-mail a sure win over traditional “snail mail.” With e-mail, it takes only minutes to send a letter, compared to days or weeks for postal mail. But the keys are often reliability and efficiency (and sometimes security). The information may be pictures, movies, programs, text, credit card information, or simple messages. The Internet is about the efficient and reliable transmission of information among many interacting parties. Many things in code-base may be changed since I left the company.Requirements: Mac OS 8 or later, Internet connection. Also, I'm not aware of new features this guy describing. I was quite happy with plain minimalist Pidgin ICQ client. I would prefer not to discuss marketing/business side of ICQ because I personally had fundamentally different opinion from AOL/Mail.Ru product owners. Native modern mobile client uses HTTP based protocol which supports recently added features.Īccording to Mail.Ru Group audited annual report, in December 2013 ICQ had 11 million monthly active users. Note that all publicly available information in the Internet about ICQ protocol describing legacy binary protocol called OSCAR. Our custom build system created C-functions which pack/unpack OSCAR messages Ĩ) Huge portion of core code-base was dedicated to create very scalable distributed server architecture Here are some quick facts about ICQ backend infrastructure:ġ) ICQ servers has over 2'700'000 lines of code which is written in C and C++ Ģ) ICQ has its own TCP/IP implementation which works in the user space ģ) Concurrency based on event-driven model (epoll), each instance handles many requests semi-simultaneously Ĥ) About 60 different interconnected internal services ĥ) Each kind of backend service is a cluster of more than a hundred of instances Ħ) C core-code is written in old-school style and I liked that ħ) OSCAR protocol is defined in TCL files. I was enjoyed working with ICQ backend code-base written by AOL (although to be honest not all code was high quality). I started to work at Mail.Ru in 2010, when Mail.Ru bought ICQ from AOL. I'm former ICQ backend developer (2010 - 2014).

Icq sound effects