Completely free and open source with no usage limits or paid tiers
True two-way synchronization rather than one-directional mirroring
Works well over slow or unreliable network connections
Encrypted synchronization over SSH for secure transfers
Long track record of active development and stability spanning more than two decades
Cons
Command-line-first design has a steeper learning curve than modern consumer sync apps
Not a continuous background sync service like Syncthing; runs are user-initiated
GUI is more basic than commercial cloud-sync applications
No built-in cloud storage or hosted service; users must provide their own destination machines
Acquia
Pros
Deep, purpose-built expertise in Drupal, backed by the CMS's original creator
Full digital experience platform spanning hosting, personalization, DAM, and customer data, not just CMS hosting
Strong fit for large, complex, multi-site, or multi-brand organizations
Enterprise-grade security, compliance, and auto-scaling infrastructure
Backed by Vista Equity Partners with substantial revenue and an established enterprise customer base
Cons
No published pricing; enterprise contracts typically run into six figures annually
Requires specialized Drupal expertise to implement and maintain effectively
Overkill and cost-prohibitive for small or mid-sized organizations
Sales and procurement cycles are long, typical of enterprise digital experience platform purchases
Use Cases
Unison
Keeping a laptop and desktop in sync — Developers and researchers use Unison to keep project files consistent between a laptop and a desktop machine without a cloud service.
Syncing between a local machine and a remote server — Sysadmins use Unison over SSH to keep files synchronized between a workstation and a remote server.
Offline-capable synchronization — Users who work disconnected from the network periodically reconnect and run Unison to reconcile changes made while offline.
Acquia
Enterprise Drupal Hosting and Management — Large organizations running mission-critical Drupal websites use Acquia Cloud Platform for auto-scaling, secure, compliant hosting with expert Drupal support.
Unified Customer Data and Personalization — Global brands use Acquia CDP and Personalization to unify customer data across channels and deliver tailored content and offers in real time.
Multi-Site, Multi-Brand Web Management — Universities, government agencies, and multi-brand companies use Acquia Site Studio to manage large portfolios of websites from a single platform with consistent governance.