custom google maps application on which a placemarker moves over the map at locations given to it at intervals--possible?

Question

Hi,

I want to know if i can create a custom google maps application,on which a placemarker continuously moves over the map accordingly as its latlongs are changing. If yes...what technologies shall i be using for such a webapp?? can this be done with .NET....Ultimately if this is possible,i will have to use this webapp on RHEL5 OS.

Secondly,i want to know if the google maps data is freely available??like if i can download the map data of a specific region at different zoom levels and then make the custom google map webapp to access the map data not from the google data centres but from the locally downloaded data??is this possible?

Thanks.

Edit1:

Ok, i got some code from code.google.com and tested a few of them... ant it was really nice.. now i want two things... 1) some map api event handler that i can use to update a marker's location at a)specific time intervals and, b)whenever my application is given some input from some other source to change the markers location..(this would be most probably an exe on linux that would be giving input to the web app)

2) i want to ajaxise all this so there are no page refreshes..

Can some one give me the eventhandlers from the api that i would be listening to?...i really searched the api reference but couldnt find one that would do my job:(

and also some inputs as to how i should ajaxise all the stuff??

Thanks.

Answer 1

1. Yes, provided google maps api allows you to modify placemark locations any way you want. However, there are some restrictions about realtime data usage on google maps, so please check terms of service.

2. Google Maps API works inside browser as a javascript code, so you have to write own javascript functions to obtain new coordinations from server and move/modify placemarks. You can also learn GWT library, which allows you to write code in "almost-java" language and compile it to Javascript, or use Adobe Flash, there is a flash API too.

3. The site itself can be programmed in any language you want, including .net (although it may be hard to serve .net sites with linux).

4. Server backend can be programmed in any technology you want, just set common data format at server and browser side (JSON format may be suitable).

5. Terms of service can be found here: http://code.google.com/apis/maps/terms.html You cannot download any map or restrict site access if you are using free google maps service.