I am looking at developing a project that will integration SaleForce with another SaaS provider using webservices. The provider has given me the specs for adding the web references within Visual Studio, but I was wondering if this is possible to do using Apex or another product in SalesForce? Whats the best solution for integrating SalesForce and another SaaS provider?

I am looking at developing a project that will integration SaleForce with another SaaS provider using webservices. The provider has given me the specs for adding the web references within Visual Studio, but I was wondering if this is possible to do using Apex or another product in SalesForce? Whats the best solution for integrating SalesForce and another SaaS provider?