# List of free and open-source web applications

All web applications, both traditional and Web 2.0, are operated by software running somewhere. This is a list of free software which can be used to run alternative web applications. Also listed are similar proprietary web applications that users may be familiar with. Most of this software is server-side software, often running on a web server.
| Application | Service | License | Requirements | Similar proprietary web application(s) |
| Collabora Online | Online office suite | MPLv2.0 | | Google Docs, Microsoft 365 |
| Gallery | Photo sharing | GPLv3 | PHP + MySQL | flickr, Picasa |
| Piwigo | Photo sharing | GPL | PHP + MariaDB / MySQL | flickr, Picasa |
| OpenBroadcaster | Video streaming | AGPLv3+ | MySQL | YouTube |
| Plumi | Video streaming | GPL | ZPL | | YouTube |
| PeerTube | Video streaming | AGPLv3+ | | YouTube |
| Libre.fm | Music streaming | AGPLv3+ | PostgreSQL or MySQL | last.fm |
| CiteSeerX | Bibliographic database | Apache | MySQL or PostgreSQL | SpringerLink |
| OpenStreetMap | Mapping | ODbL | MySQL or PostgreSQL | Google Maps |
| ownCloud | File sharing/sync, web calendar, online office suite etc. | AGPLv3 | | Dropbox, drop.io |
| Nextcloud | File sharing/sync, web calendar, online office suite etc. | AGPLv3+ | PHP + MariaDB / MySQL / Oracle / PostgreSQL / SQLite | Dropbox, Google Drive, Microsoft 365, box |
| Seafile | File sharing/sync, web calendar, online office suite etc. | GPLv2 | | Dropbox, drop.io |
| Tahoe Least-Authority File Store | File sharing | GPLv2+ | | Dropbox, drop.io |
| iFolder | File sharing | GPLv2+ | | Dropbox, drop.io |
| AbiCollab | Online file editing | GPLv2 | MySQL or PostgreSQL | Google Docs |
| Etherpad | Online file editing | Apache | MySQL or PostgreSQL | Google Docs |
| Eucalyptus (computing) | Virtual machine provisioning | GPLv3 | | Amazon EC2 |
| OpenNebula | Virtual machine provisioning | Apache | SQLite3 | Amazon EC2 |
| DokuWiki | Wiki | GPLv2 | | Wikispaces |
| MediaWiki | Wiki | GPLv2+ | MySQL or PostgreSQL | Wikispaces |
| TiddlyWiki | Wiki | BSD license | Web browser | Evernote, Microsoft OneNote |
| Open Journal Systems | Publication management | GPLv2 | MySQL or PostgreSQL | |
| WordPress | Blogging | GPLv2 | PHP + MariaDB / MySQL | blogger.com |
| LiveJournal | Blogging | GPLv2+ | | blogger.com |
| Ghost | Blogging | MIT License | JavaScript, node.js | blogger.com |
| GNU Social | Distributed social network | AGPLv3 | MySQL or PostgreSQL | Twitter |
| Mastodon | Distributed social network | AGPLv3 | PostgreSQL | Twitter |
| AppScale | Virtual web hosting | BSD | | Google AppEngine |
| PHPGroupware | Online office suite | GPLv2 | | Google Docs |
| eGroupware | Online office suite | GPLv2 | | Google Docs |
| Feng Office | Online office suite | AGPL | | Google Docs |
| Roundcube | Web mail | GPLv3+ with exceptions for skins and plugins | | Gmail, Hotmail |
| IMP | Web mail | GPLv2 | IMAP server | Gmail, Hotmail |
| Squirrelmail | Web mail | GPLv2 | | Gmail, Hotmail |
| Mailman | Mailing lists | GPL | | Google Groups, Yahoo Groups |
| FluxBB | Forum | GPLv2 | | |
| phpBB | Forum | GPLv2 | | |
| MyBB | Forum | GNU LGPL | | |
| Phorum | Forum | Phorum 2.0 | | |
| Vanilla | Forum | GPLv2 | | |
| Discourse | Forum | GPLv2+ | | |
| LimeSurvey | Internet survey | GPLv2 | | SurveyMonkey, Google Form creator |
| Tiny Tiny RSS | RSS reader | GPLv3 | | Google Reader |
| pump.io | Social aggregation | Apache | | FriendFeed |
| Meneame | Social news | AGPLv3 | | Digg |
| Mixx | Social news | | | Digg |
| Friendica | Distributed social network | MIT | | Facebook |
| Diaspora | Distributed social network | AGPL | | Facebook |
| BuddyPress | Distributed social network | GPL | WordPress | Facebook |
| Elgg | Distributed social network | GPLv2 / MIT | | Facebook |
| Scuttle | Social bookmarking | | | Delicious |
| Connotea (discontinued) | Social bookmarking | | | Delicious |
| Ma.gnolia 2 (discontinued) | Social bookmarking | | | Delicious |
| Apertium | Translation | GPLv2 | | Google Translate |
| EyeOS (version 2.5 and earlier) | Homepage | AGPLv3 | | iGoogle |
| OpenCroquet | Virtual world | MIT | | SecondLife |
| OpenSimulator | Virtual world | BSD | | SecondLife |
| bitwarden | Password manager | GPLv3, AGPLv3 | node.js | Dashlane, LastPass |
| Mattermost | Web chat | MIT, AGPLv3, Apache License 2.0 | | Slack |
| Element | Web chat | Apache License 2.0 | | Slack |