I have a simple solution with the following projects as follows (base namespaces match the project name)...
MyCompany.MyProduct.BusinessLayer
MyCompany.MyProduct.Web.Service
MyCompany.MyProduct.Web.Site
I'm just trying to find a better name for BusinessLayer, I just don't really like it for some reason. So my question is what do you call your BusinessLayer projects/namespaces.
article on namespace guidelines http://msdn.microsoft.com/en-us/library/ms229026.aspx
Ours are:
CompanyName.CentralClassLibrary
CompanyName.Utilities.*
CompanyName.TradingTools.*
The first is mostly classes from the original version of our application, which describe the central trading objects. The second is classes that provide non-trading specific functionality (configuration, multi-machine, etc.) The third is for specific domains of trading (one for each service we talk to, one for calculating value, etc.)
We just use BL because it stands for both Business Layer and BudLight.
In Java, I use the com.companyname.applicationname.* "standard," even though it's a little old-school.
In C#, I use the CompanyName.ApplicationName.* approach.
In both cases * will usually be business for the business layer, data for the data layer, and so on.
Our Business Logic and Data Access Layers
CompanyName.ApplicationName.BLL CompanyName.ApplicationName.DAL
An alternative might be BusObj or something like that.
I've seen BusinessLogic, but it as noted by the rest of the answers here a lot of time you will see...
Another good reference for this type of stuff is the Framework Design Guidelines book.
Most of the apps we work on use DAL for Data Access Layer and BR for Business Rules...