Twitter reached a major milestone today with the launch of its website in four right-to-left languages. The popular microblogging service is now available in Arabic, Hebrew, Farsi, and Urdu.

Twitter today said in a blog post that it added the four languages to its Twitter Translation Center and that 13,000 volunteers answered the call to help out. According to Twitter, the group of volunteers was as diverse as it is large with helpers coming from all parts of the globe—some in countries were Twitter is banned— in a number of different professions including a “Saudi blogger, Egyptian college students, a journalist at the BBC, IT professionals in Iran and Pakistan, an Israli school teacher, the co-founders of the grassroots #LetsTweetinArabic campaign,” and many more.

The Twitter Translation Center was launched in February of last year when Twitter was only available in seven languages. It called on volunteers to help translate the service into new languages like Russian, Indonesian, and Turkish. Twitter is now available in 28 languages.

[via BBC, Twitter]