| O | 1 | 1 |
| O-Dyn | 1 | 16 |
| O-Kiraku Nikki | 1 | 1 |
| O-Ran-Sc | 3 | 5 |
| O.Bike | 2 | 2 |
| O2Php | 2 | 2 |
| O2Php.Com | 1 | 2 |
| O2Tweet Project | 1 | 1 |
| Oaboard | 1 | 3 |
| Oacstudio | 1 | 1 |
| Oaooa | 1 | 1 |
| Oar Project | 1 | 1 |
| Oasis-Open | 1 | 1 |
| Oasys Project | 1 | 1 |
| Oasyssoft | 1 | 3 |
| Oatmeal Studios | 1 | 1 |
| Oauth Client Single Sign On Project | 1 | 3 |
| Oauth-Ruby Project | 1 | 2 |
| Oauth2 Proxy Project | 1 | 7 |
| Oauth2-Server Project | 1 | 3 |
| Oauth2Orize-Fprm Project | 1 | 1 |
| Oauthlib Project | 1 | 1 |
| Obdasystems | 1 | 2 |
| Obdev | 1 | 5 |
| Obeo | 1 | 1 |
| Oberhumer | 2 | 2 |
| Oberthur | 1 | 1 |
| Obg | 1 | 1 |
| Obie Website | 1 | 3 |
| Object-Extend Project | 1 | 1 |
| Object-Path Project | 1 | 3 |
| Objectcomputing | 3 | 11 |
| Objectfirst | 1 | 3 |
| Objection Project | 1 | 1 |
| Objectiv | 1 | 1 |
| Objective Development | 3 | 5 |
| Objective Open Cbor Run-Time Project | 1 | 1 |
| Objective Systems | 1 | 1 |
| Objective-See | 5 | 5 |
| Objectivity | 1 | 1 |
| Objectledger | 1 | 2 |
| Objectplanet | 1 | 6 |
| Objectweb | 1 | 1 |
| Obl.Ong | 1 | 1 |
| Oblius | 1 | 1 |
| Oblix | 1 | 1 |
| Obm | 1 | 5 |
| Obottle Project | 1 | 2 |
| Obox | 1 | 2 |
| Obridge Project | 1 | 1 |
| Obs-Server | 1 | 1 |
| Observium | 1 | 20 |
| Obsession-Design | 1 | 1 |
| Obsidian | 2 | 6 |
| Obspm | 1 | 1 |
| Obss | 1 | 1 |
| Obstack Project | 1 | 1 |
| Obtaininfotech | 2 | 3 |
| Obtcoin Project | 1 | 1 |
| Obyte | 1 | 1 |
| Oc-Server3 Project | 1 | 3 |
| Ocaml | 2 | 5 |
| Ocaml Batteries Project | 1 | 1 |
| Occlum Project | 1 | 1 |
| Ocdi | 1 | 3 |
| Oce North America | 2 | 2 |
| Ocean12 Technologies | 6 | 14 |
| Ocean12Tech | 3 | 6 |
| Oceanavenue | 1 | 1 |
| Oceandir | 1 | 1 |
| Oceanicsoft | 1 | 5 |
| Oceanwp | 2 | 18 |
| Ocf | 1 | 1 |
| Ocimscripts | 1 | 1 |
| Oclc | 1 | 1 |
| Oclean | 1 | 1 |
| Ocomon | 1 | 4 |
| Ocomon Project | 1 | 6 |
| Ocp2 | 1 | 1 |
| Ocpfoundation | 2 | 2 |
| Ocportal | 1 | 6 |
| Ocproducts | 1 | 3 |
| Ocshield | 1 | 1 |
| Ocsinventory-Ng | 5 | 20 |
| Octavocms | 1 | 1 |
| Octavolabs | 1 | 2 |
| Octech | 1 | 2 |
| Octeth | 1 | 4 |
| Octobercms | 2 | 48 |
| Octobot | 1 | 1 |
| Octobox Project | 1 | 1 |
| Octokit | 3 | 3 |
| Octokit Project | 1 | 1 |
| Octolize | 1 | 5 |
| Octopoller Project | 1 | 1 |
| Octoprint | 1 | 17 |
| Octopus | 5 | 90 |
| Octopussy | 1 | 1 |
| Oculus | 2 | 3 |
| Odallated | 1 | 1 |
