Globus XIO is a new component as of Globus 3.2. Previous versions of Globus provided an API called globus_io. XIO is a replacement for globus_io; however a compatibility layer exists to allow full backward compatibility for applications written against globus_io. For users familiar with globus_io the learning curve for XIO will be very small. The APIs use the same event model and only significantly differ in connection establishment.

Globus XIO has made very few changes in the API since its introduction. User of GT4.0 who are previously familiar with globus_xio will notice no difference.