The 10.05 percent usage was up from 9.75 percent in February.
Microsofts Internet Explorer still holds a commanding lead with 84.7 percent of the market, Net Applications said.
However, according to another analytics firm, Firefox had already surpassed 10 percent market share last November.
OneStat.com reported at the time that Mozilla browsers had reached 11.51 percent usage globally based on a sample of 2 million users from 100 companies.
Despite the conflicting numbers, its clear that Firefox continues to gain a foothold--especially overseas. Internet Explorer, meanwhile, is continuing its slow slide.