lsyncd vs Unison
No leader: the top candidate Unison has only 0.26 confidence (low), below the 0.35 needed to declare a winner. The attribute-by-attribute breakdown below, with a source and date on every value, is the honest way to compare them.
Capabilities
Feature-by-feature on the axes that matter for file sync. “-” means undocumented, not absent.
What each one is
The product in its own terms, so the numbers below have context.
lsyncd
Lsyncd actively watches local file systems for modifications using filesystem event interfaces, then automatically copies those changes to remote systems. It supports rsync and rsync+ssh as synchronization protocols and offers customization through configuration files and Lua scripting.
Unison
Unison is an open-source utility that maintains two replicas of files and directories across separate hosts or storage devices, automatically propagating non-conflicting changes while detecting conflicting updates. It works over internet connections including slow links, and allows offline access to already-synchronized data.
Pricing
List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.
Platform & deployment
Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.
Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.