Windows Server 2019 Alternatives

PetaSAN is an open source Scale-Out SAN solution offering massive scalability and performance.

FreeNAS is a storage operating system strong and robust enough to meet the needs of enterprise level businesses.

Powerful SaaS integration toolkit for SaaS developers - create, amplify, manage and publish native integrations from within your app.

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Being a Software-Defined Storage (SDS) solution, StarWind Virtual SAN (VSAN) eliminates any need for physical shared storage and delivers high performance.

SvSAN is a virtual SAN for Hypervisors.

VMware vSAN is radically simple, enterprise-class software-defined storage powering VMware hyper-converged infrastructure. 

Simplify your IT with HPE Simplivity hyper converged infrastructure, your all-in one management solution for hybrid cloud and VM efficiency, scalability.

Compuverde is built to scale and it scales linearly.

Dell EMC VxRack System SDDC provides the easiest and fastest way to stand up a complete VMware based cloud infrastructure environment at rack scale.

Rockstor is a free and open source NAS (Network Attached Storage) operating system.

NetApp HCI and SolidFire bring together the best of the public cloud and the private cloud to create a seamless user experience and to help you build a true hybrid multi cloud experience.

Get Open-E DSS V7 SOHO (Small Office Home Office), a free version of Open-E DSS V7 with basic functionalities of NAS/SAN software platform.

Simplicity. Flexibility. Scalability. Modularity. Unraid empowers you to build the system you’ve always wanted using your preferred hardware, software, and operating systems.

Univention Corporate Server UCS with Active Directory functions and App Center is the cost-efficient and popular successor to Microsoft's server solutions.