01/ Samba
Best for: Windows file sharing and Active Directory domains on Linux.
Open source; implements the SMB and Active Directory protocols that Windows clients use.
Runs on: Linux
Visit SambaDevelopment & IT · File sharing and directory services
Free alternatives to Windows Server
Windows Server by Microsoft: Server operating system for file sharing, Active Directory and business apps. Pricing: per-core licence. Here are 2 free options that cover the same job.
| Alternative | Type | Platforms | Best for | |
|---|---|---|---|---|
SambaOpen source; implements the SMB and Active Directory protocols that Windows clients use. | Compatible | Linux | Windows file sharing and Active Directory domains on Linux | Get it |
TrueNAS Community Edition | Open source | Server | A network storage server with Windows (SMB) shares | Get it |
 Windows ServerThe paid original | Per-core licence | – | File sharing and directory services | Visit |
The alternatives in detail
02/ TrueNAS Community Edition
Best for: A network storage server with Windows (SMB) shares.
Runs on: Server
Visit TrueNAS Community EditionAbout “Compatible” tools: An independent, legal re-implementation that opens the same files or runs the same software. Not a cracked copy.
Frequently asked questions
Is there a free alternative to Windows Server?
Yes. Samba is a strong free option for windows file sharing and active directory domains on linux. Other choices include TrueNAS Community Edition.
Which Windows Server alternative is open source?
Samba, TrueNAS Community Edition are open source.
Are compatible (reverse-engineered) alternatives legal?
Yes. Tools marked Compatible are independent re-implementations built to open the same files or run the same software. They do not contain the original program's code. They are not cracked or pirated copies, which we never recommend.