Apple's share of the global operating system market is climbing steadily, and could top 8% this month, statistics from a Web metrics firm showed Wednesday.

The latest monthly numbers from Net Applications show that Mac OS X had 7.94% of the market in June. Considering that its share has been climbing an average of 0.18% a month over the last 10 months, Mac OS X could top 8% this month. In August 2007, the Apple OS had 6.18% of the market.

During the same period, Linux has also increased market share, rising to 0.8% of the market in June from 0.47% last August, according to Net Applications. Meanwhile, the global market share of Microsoft Windows has declined over the last 10 months. In June, Windows accounted for 90.89% of the market, down from 93.06%.

While monthly market-share numbers from Net Applications are not definitive, they are an indication that Apple has been gaining in the market, as sales of Mac computers soar. In April, Apple reported Mac shipments in the first three months of the year were up 51% from the same period a year ago. Revenue rose by 54%.

In updating its iMac line in April with faster Intel Core 2 duo processors, Apple noted that Mac sales have been growing at a rate 3.5 times faster than PC sales. Research firm IDC reported the same month that Apple's share of the U.S. PC market during the first quarter reached 7.1%, up from 4.9% in the same period last year. The increase represented a growth rate of 45%.

Dell's share of the U.S. PC market during the same time frame also increased. The computer maker, which ships mostly Windows machines, saw its share rise to 30.9% from 27.2% a year ago, representing 15.6% growth. Dell is the largest computer maker in the United States in terms of shipments, according to IDC.