1. Cost of Ownership: Microsoft SharePoint is a paid platform, while Nextcloud is open-source with a range of pricing options. This makes Nextcloud more cost-effective for small businesses or organizations on a budget. SharePoint requires a license fee, additional costs for hardware, and ongoing maintenance expenses, whereas Nextcloud offers flexibility in terms of pricing, including free options for basic usage.
2. Deployment Options: SharePoint is typically deployed on-premises or in the cloud with Microsoft 365, while Nextcloud can be deployed on-premises or on a self-hosted server. This gives Nextcloud users the ability to have full control over their data and infrastructure, while SharePoint users may have less control if they opt for the cloud-based deployment.
3. Collaboration and Communication Features: SharePoint provides robust collaboration and communication features, such as document management, version control, workflows, and integration with Microsoft Office tools. Nextcloud offers similar features, including document collaboration, file sharing, chat, and integration with office productivity tools like OnlyOffice or Collabora Online. However, SharePoint might have a slight advantage in terms of deeper integration within the Microsoft ecosystem.
4. Customizability and Extensibility: SharePoint offers a wide range of customization options and has a mature ecosystem of third-party solutions. It allows for the creation of custom workflows, forms, and applications using Microsoft's development tools. Nextcloud, on the other hand, is highly customizable and extensible as well, with a large number of available apps and integrations that can be easily installed from the Nextcloud App Store.
5. Security and Compliance: Both SharePoint and Nextcloud offer various security features, including user access controls, encryption, and audit logs. However, SharePoint, as part of the Microsoft ecosystem, may provide tighter integration with Microsoft 365 security services. On the other hand, Nextcloud allows for complete control over data storage, enabling organizations to comply with specific data security and privacy regulations more easily.
6. File Synchronization and Mobile Access: Nextcloud excels in providing robust file synchronization and mobile access features. It offers synchronization capabilities across devices, allowing users to access and work on files offline. Nextcloud's mobile applications are well-developed and provide seamless access to files, calendars, and contacts on both Android and iOS devices. SharePoint also offers file synchronization and mobile access, but Nextcloud's focus on mobility and cross-platform support gives it an edge in this area.

In summary, Microsoft SharePoint is a paid platform with advanced integration within the Microsoft ecosystem, offering robust collaboration and communication features. Nextcloud, on the other hand, is open-source with flexible pricing options, providing customization, control, and strong file synchronization and mobile access capabilities.