Do we have an object for SharingObjects on which we can run soql ?

Is there a way to get the opportunity share details to the User level using SOQL.Is there any SFDC object for this.Currently in OpportunityShare object we get both user as well as groupid.And from group(which can be group or role) we need to find the group members.

I have a piece of Javascript code running fine on a Visualforce Page.The code is referring to a Static resource and it is also working fine.
I need to execute the same JS through custom link ,so that it can be added as a sidebar component on standard pages.
Can someone please suggest what modifications need to be done to the JS so that it can work from Custom Link.

Thanks,
Rakesh 

Do we have an object for SharingObjects on which we can run soql ?

I have a piece of Javascript code running fine on a Visualforce Page.The code is referring to a Static resource and it is also working fine.
I need to execute the same JS through custom link ,so that it can be added as a sidebar component on standard pages.
Can someone please suggest what modifications need to be done to the JS so that it can work from Custom Link.

Thanks,
Rakesh