Recent developments of global computing systems such as Ninf, NetSolve and Globus have opened up the opportunites for providing high-performance computing services over wide-area networks. However, most research focused on the individual architectural aspects of the system, or application deployment examples, instead of the necessary charactersistics such systems should intrinsically satisfy, nor how such systems relate with each other. Our comparative study performs deployment of example applications of network-based libraries using Ninf, NetSolve, and CORBA systems. There, we discover that dedicated systems for global computing such as Ninf and NetSolve have management, progammability, and in does not suffer performance disadvantages over more generic distributed computing capabilities provided by CORBA. Such results indicate the advantage of dedicated global computing systems over general systems, stemming further basic research is necessary across multiple systems to identify the ideal software architectures for global computing.