What is SLurl?
SLurl provides direct teleport links to locations in Second Life. If you have Second Life installed, clicking on the map link will automatically teleport you to that location in-world.
Why use SLurl?
In addition to allowing customized control over mapping locations in Second Life, SLurl also provides a better experience for web users who don't have Second Life. Instead of getting an error when clicking on web links that begin with "secondlife://", visiting a SLurl link gives potential new users a chance to sign up.
Also, check out this SLurl Builder, a handy online tool to help you build your direct links to SL locations.