Some of the pros of ASP is that since it primarily uses VBScript it' s relatively easy to pick up the language if you're already know how to program in Visual Basic.
ASP is not really a language in itself, it's an acronym for Active Server Pages, the actual language used to program ASP with is Visual Basic Script or JScript. The biggest drawback of ASP is that it's a proprietary system that is natively used only on Microsoft Internet Information Server (IIS). This limits it's availability to Win32 based servers. There are a couple of projects in the works that allows ASP to run in other environments and webservers: InstantASP from Halcyon (commercial), Chili!Soft ASP from Chili!Soft (commercial) and OpenASP from ActiveScripting.org (free). ASP is said to be a slower and more cumbersome language than PHP, less stable as well. Some of the pros of ASP is that since it primarily uses VBScript it's relatively easy to pick up the language if you're already know how to program in Visual Basic. ASP support is also enabled by default in the IIS server making it easy to get up and running. The components built in ASP are really limited, so if you need to use "advanced" features like interacting with FTP servers, you need to buy additional components.