What are the requirement to see the map in 3D?

A computer and a browser supporting WebGL (check outWebGL blacklist if it does not work)
Windows XP and Vista have been black listed on Chrome since version 32, to force activation you can enableOverride software rendering list underchrome:flags

How to contact F4 map team?

You cancontact us directly.

How does the 3D rendering work?

We based our generation onsimple 3D buildings.
Check out how we handle 3D tags on3D Render page.

How can i see the map with relief?

Relief can be enabled/disabled from the graphic option page from the top right Menu.

How much time does it take for my modifications to show up?

Short answer:
About a day.
Long answer:
Osm data should be synchronized in "real time", you can usually expect about 5min delay.
However, we use a 24 hours cache on server side, so any modification you make can take up to 24h before showing up.