Swahili is the second African language after Afrikaans to be on Facebook
The social-networking website Facebook has launched in Swahili, targeting more than 110m speakers of the language.
A group of Swahili scholars launched the new version with the permission of the California-based internet firm.
Facebook use has spread over the past five years in East and Central Africa, where most Swahili-speakers live.
Analysts say a Hausa version could be launched next in West Africa and Zulu for southern Africa. Facebook already exists in Afrikaans.
Symon Wonda, one of the project's initiators, said they wanted to launch a Swahili version to safeguard the future of the language.
"The youth, the future generation, if you look at the biggest percentage of users on Facebook, they are the youth," he told the BBC's Network Africa programme.
"They can easily navigate through when it's maybe a language they understand, which makes it easier to use the Swahili than to use the English."
The BBC's Ruth Nesoba, in Nairobi, says the Swahili site has already been on trial for some time and word has spread quickly.
The bulk of Swahili-speakers live in Kenya, Tanzania, Uganda, eastern Democratic Republic of Congo, parts of the Horn of Africa, Malawi, Mozambique and the Indian Ocean islands.
Facebook already exists in some 50 language versions.