Fit: PartialCore overlap exists; named gaps need replacing or rebuilding.Fit is not feature parity.ATier ANo paid feature gates in the self-run editionMozilla Public License 2.0Permissions of this weak copyleft license are conditioned on making available source code of licensed files and modifications of those files under the same license (or in certain cases, one of the GNU licenses). Copyright and license notices must be preserved. Contributors provide an express grant of patent rights. However, a larger work using the licensed work may be distributed under different terms and without source code for files added in the larger work.MayCommercial useModificationDistributionPatent usePrivate useMustDisclose sourceLicense and copyright noticeSame license (file)NoLiabilityTrademark useWarrantySummary from GitHub's choosealicense.comSelf-hostable: yesYou can run it on your own server.
Editor component for documents/spreadsheets/slides, requiring external file storage/authentication such as Nextcloud, ownCloud or Seafile. Does not supply the full email/calendar/meetings/storage suite; test Office-format, macro and layout fidelity. CODE rolling builds carry production stability caveat.
Fit: PartialCore overlap exists; named gaps need replacing or rebuilding.Fit is not feature parity.ATier ANo paid feature gates in the self-run editionGNU General Public License v3.0Permissions of this strong copyleft license are conditioned on making available complete source code of licensed works and modifications, which include larger works using a licensed work, under the same license. Copyright and license notices must be preserved. Contributors provide an express grant of patent rights.MayCommercial useModificationDistributionPatent usePrivate useMustLicense and copyright noticeState changesDisclose sourceSame licenseNoLiabilityWarrantySummary from GitHub's choosealicense.comSelf-hostable: yesYou can run it on your own server.
Replaces custom-domain mailbox hosting, not the full office suite. Mailcow sync jobs copy messages from IMAP; calendars, contacts, permissions and client behavior need separate migration checks. Operator manages DNS, deliverability, backups and upgrades.
Fit: PartialCore overlap exists; named gaps need replacing or rebuilding.Fit is not feature parity.BTier BPaid extras for admin, identity or auditGNU Affero General Public License v3.0Permissions of this strongest copyleft license are conditioned on making available complete source code of licensed works and modifications, which include larger works using a licensed work, under the same license. Copyright and license notices must be preserved. Contributors provide an express grant of patent rights. When a modified version is used to provide a service over a network, the complete source code of the modified version must be made available.MayCommercial useModificationDistributionPatent usePrivate useMustLicense and copyright noticeState changesDisclose sourceNetwork use is distributionSame licenseNoLiabilityWarrantySummary from GitHub's choosealicense.comSelf-hostable: yesYou can run it on your own server.
Broad collaboration hub: file sync/share, groupware, calls and document collaboration via apps. Configure an office engine and existing email server/provider; not a replacement for all proprietary desktop features, advanced formulas/macros, tenant identity or compliance services. Export native cloud document formats to portable Office/ODF files and pilot fidelity before migrating.
Fit: PartialCore overlap exists; named gaps need replacing or rebuilding.Fit is not feature parity.CTier CDaily-workflow features need a paid editionGNU Affero General Public License v3.0Permissions of this strongest copyleft license are conditioned on making available complete source code of licensed works and modifications, which include larger works using a licensed work, under the same license. Copyright and license notices must be preserved. Contributors provide an express grant of patent rights. When a modified version is used to provide a service over a network, the complete source code of the modified version must be made available.MayCommercial useModificationDistributionPatent usePrivate useMustLicense and copyright noticeState changesDisclose sourceNetwork use is distributionSame licenseNoLiabilityWarrantySummary from GitHub's choosealicense.comSelf-hostable: yesYou can run it on your own server.
Office editing component, typically integrated with sync/share storage. Not the complete mail/calendar/file suite; Docs Community has 20-editing-connection ceiling and no mobile browser editing. Export native Google documents first; test complex Office documents and integrations.
Fit: PartialCore overlap exists; named gaps need replacing or rebuilding.Fit is not feature parity.BTier BPaid extras for admin, identity or auditApache License 2.0A permissive license whose main conditions require preservation of copyright and license notices. Contributors provide an express grant of patent rights. Licensed works, modifications, and larger works may be distributed under different terms and without source code.MayCommercial useModificationDistributionPatent usePrivate useMustLicense and copyright noticeState changesNoTrademark useLiabilityWarrantySummary from GitHub's choosealicense.comSelf-hostable: yesYou can run it on your own server.
Replaces Drive/OneDrive file sync/share portion with team spaces and WebDAV APIs; Office editors integrated separately. Mail/calendar/meetings and proprietary tenant services require other products. Choose source or vendor build after checking relevant distribution terms.
Fit: PartialCore overlap exists; named gaps need replacing or rebuilding.Fit is not feature parity.CTier CDaily-workflow features need a paid editionGNU Affero General Public License v3.0Permissions of this strongest copyleft license are conditioned on making available complete source code of licensed works and modifications, which include larger works using a licensed work, under the same license. Copyright and license notices must be preserved. Contributors provide an express grant of patent rights. When a modified version is used to provide a service over a network, the complete source code of the modified version must be made available.MayCommercial useModificationDistributionPatent usePrivate useMustLicense and copyright noticeState changesDisclose sourceNetwork use is distributionSame licenseNoLiabilityWarrantySummary from GitHub's choosealicense.comOpenSSL linking exception (custom license)Not a standard license, so GitHub's license summaries don't cover it. Read the project's license text before relying on it.Self-hostable: yesYou can run it on your own server.
Replaces Drive/OneDrive-style file sync/share portion only; Office editing requires an external editor integration. Email, meetings and full suite absent; full-text file search and fine-grained permissions are paid Professional features.
Fit: PartialCore overlap exists; named gaps need replacing or rebuilding.Fit is not feature parity.CTier CDaily-workflow features need a paid editionGNU Affero General Public License v3.0Permissions of this strongest copyleft license are conditioned on making available complete source code of licensed works and modifications, which include larger works using a licensed work, under the same license. Copyright and license notices must be preserved. Contributors provide an express grant of patent rights. When a modified version is used to provide a service over a network, the complete source code of the modified version must be made available.MayCommercial useModificationDistributionPatent usePrivate useMustLicense and copyright noticeState changesDisclose sourceNetwork use is distributionSame licenseNoLiabilityWarrantySummary from GitHub's choosealicense.comSelf-hostable: yesYou can run it on your own server.
Replaces standards-based email/calendar/contact hosting, not Google or Microsoft office apps and vendor automation. Pilot IMAP/CalDAV/CardDAV migration and client behavior; vendor service migration claims do not establish a turnkey Google Workspace or Exchange Online migration. Recovery and AI mail features require Enterprise.
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Mozilla Public License 2.0 Permissions of this weak copyleft license are conditioned on making available source code of licensed files and modifications of those files under the same license (or in certain cases, one of the GNU licenses). Copyright and license notices must be preserved. Contributors provide an express grant of patent rights. However, a larger work using the licensed work may be distributed under different terms and without source code for files added in the larger work. May Commercial useModificationDistributionPatent usePrivate use Must Disclose sourceLicense and copyright noticeSame license (file) No LiabilityTrademark useWarranty Summary from GitHub's choosealicense.com Self-hostable: yesYou can run it on your own server. 
