It has a "Web Retrosocial" license ( if you have benefits must be destined to child aid efforts ).
This application is implemented over Ruby on Rails and is created by Flowers In Space.
| Name | Description/Focus | Registered users | Registration |
| Bebo | General, Popular in UK, Ireland, New Zealand and the Pacific Islands | 40.000.000 | Open to people 13 and over |
| Classmates.com | School, college, work and the military | 40.000.000 | Open |
| Windows Live Spaces | Blogging (formerly MSN Spaces) | 40.000.000 | Open |
| Xanga | Blogs and "metro" areas | 40.000.000 | Open |
| Flixster | Movies | 36.000.000 | Open |
| Tagged.com | General | 30.000.000 | Open |
| Netlog | Formerly known as Facebox. | 28.000.000 | Open |
| Reunion.com | Locating friends and family, keeping in touch | 28.000.000 | Open |
| Broadcaster.com | Video sharing and webcam chat | 26.000.000 | Open |
| Cyworld | Young South Koreans | 21.200.000 | Open |
| Friends Reunited | School, college, work, sport and streets | 19.000.000 | Open |
| BlackPlanet | African-Americans | 16.000.000 | Open |
| imeem | Music, Video, Photos, Blogs | 16.000.000 | Open |
| LiveJournal | Blogging | 12.900.000 | Open (OpenID) |
| Fotolog | Photoblogging | 12.695.007 | Open |
| Mixi | Japan | 9.830.000 | Invite-only |
| Gaia Online | Anime and games | 9.300.000 | Open |
| Care2 | Green living and social activism | 8.123.058 | Open |
| Odnoklassniki.ru | General. Popular in Russia | 8.000.000 | Open |
| WAYN | Travel and lifestyle | 8.000.000 | Open to people 18 and older |
| Multiply | Real world relationships | 7.500.000 | Open |
| Hyves | Dutch | 5.000.000 | Open |
| Passado | General | 4.700.000 | Open |
| Yahoo! 360° | Linked to Yahoo! IDs | 4.700.000 | Open to people 18 and older, (Yahoo! login) |
| Flickr | Photo sharing | 4.000.000 | Open (Yahoo! login) |
| StudiVZ | University students, mostly in the German-speaking countries | 4.000.000 | Open |
| Soundpedia | Music | 3.500.000 | Open |
| iWiW | Hungary | 3.100.000 | Invite-only |
| Meetup.com | General | 2.000.000 | Open |
| CarDomain | Car enthusiasts | 1.600.000 | Open |
| Grono.net | Poland | 1.350.000 | Invite-only |
| Stickam | Live video streaming and chat. | 1.305.051 | Open |
| LunarStorm | Sweden | 1.200.000 | Open |
| Nexopia | Canada | 1.158.531 | Open |
| My Opera Community | General (blogs, photo albums, forums, groups, etc.) | 1.001.798 | Open |
| myYearbook | General | 950.000 | Open |
| Student.com | International teens and colleges | 850.000 | Open |
| OkCupid | Social networking and dating | 800.000 | Open |
| TravBuddy.com | Travel | 760.000 | Open |
| Geni.com | Families, genealogy | 750.000 | Open |
| tribe.net | General | 602.876 | Open |
| Buzznet | Music and pop-culture | 550.000 | Open |
| Playahead | Swedish teenagers | 530.000 | Open |
| Sconex | American high schools | 500.000 | Open |
| IRC-Galleria | Finland | 465.000 | Open |
| Gather | Article, picture, and video sharing, as well as group discussions | 450.000 | Open |
| CouchSurfing | Hospitality | 402.000 | Open |
| DontStayIn | Clubbing (primarily UK) | 333.000 | Open |
| Hospitality Club | Hospitality | 328.629 | Open |
| Ryze | Business | 250.000 | Open |
| LibraryThing | Book lovers | 214.425 | Open |
| aSmallWorld | European jet set and social elite | 150.000 | Invite-only |
| TakingITGlobal | Social action | 145.000 | Open |
| Travellerspoint | Travel | 105.000 | Open |
| ProfileHeaven | British teens | 100.000 | Open |
| MEETin | General | 72.000 | Open |
| MyChurch | Christian Churches | 70.306 | Open |
| Sermo | Physicians | 40.000 | Open only to registered D.O.s and M.D.s in the U.S.A. |
| Woophy | travel & photography, photo sharing website | 23.000 | Open |
| Consumating | Consumeetings | 21.000 | Open |
| Wis.dm | Questions and answers about anything and everything | 20.000 | Open |
| Sportsvite | Recreational sports | 18.000 | Open |
| Passportstamp | Travel | 12.000 | Open |
| Frühstückstreff | General | 11.600 | Open |
| Advogato | Free and open source software developers | 11.000 | Open |
| ANobii | Books | Unknown | Open |
| Cake Financial | Investing | Unknown | Open |
| Capazoo | General (blogs, photos, music, videos) | Unknown | Open |
| Dandelife | Collective narratives or "shared biographies" | Unknown | Open |
| Dodgeball | Mobile location-based service. Owned by Google. | Unknown | Open |
| Experience Project | Life experiences | Unknown | Open |
| Faceparty | General. Popular UK. | Unknown | Open to people 16 and older. |
| GuildCafe | Online games | Unknown | Open |
| Jaiku | General. Owned by Google. | Unknown | Open |
| Joga Bonito | Football (soccer) | Unknown | Open |
| MOG | Music | Unknown | Open |
| OUTeverywhere | Gay | Unknown | Open |
| Phanfare | Family photo and video sharing | Unknown | Open |
| Pownce | Websites, files, and short updates | Unknown | Invite-only |
| RateItAll | General (consumer ratings) | Unknown | Open |
| Searchles | Social search and networking | Unknown | Open |
| Shelfari | Books | Unknown | Open |
| Micro-blogging, RSS, updates | Unknown | Open | |
| Utterz | Micro-blogging, RSS, Audio updates via mobile device. Reads text messages over the phone. | Unknown | Open |
| Vox | Blogging | Unknown | Open |
| WebBiographies | Genealogy and biography | Unknown | Open |
| Yahoo! Mash | Yahoo's new SNS - Still in beta | Unknown | Invite-only while in beta |
| Zooomr | Universal photo sharing | Unknown | Open (OpenID) |
| Name | Description/Focus | Registered users | Registration |
| MySpace | General. Popular in the USA, UK and Australia. | 217.000.000 | Open |
| Habbo | General. Over 31 communities worldwide. Chat Room and user profiles. | 82.000.000 | Open to people 13 and older |
| orkut | Owned by Google. Popular in Brazil and India. | 67.000.000 | Open (Google login) |
| General. Popular in Canada, UK and USA. | 58.000.000 | Open to people 13 and older. | |
| Friendster | General | 50.000.000 | Open |
| hi5 | General. Latin American and Asian teens. | 50.000.000 | Open |
| Business | 17.000.000 | Open | |
| Plaxo | Business | 15.000.000 | Open |
| Badoo | General, Popular in Europe | 12.500.000 | Open to people 18 and over |
| Business | 4.000.000 | Open | |
| MiGente.com | Latinos | 3.600.000 | Open |