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

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

How to contact F4 map team?

You can use the support button footer or contact us directly on the support site.

How does the 3D rendering work?

We based our generation on simple 3D buildings.
Check out how we handle 3D tags on 3D 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.