The survey, by internet monitoring firm Netcraft, found Apache was on 48.42 per cent of web servers, with Microsoft on 36.21 percent.
In a similar survey carried out in November 2005 Apache was on 71 percent of web servers while Microsoft struggled to make 20 percent.
"Apache's lead remains substantial in both categories," said Netcraft in a statement.
"It's worth noting that Apache has lost market share to another open source server, lighttpd (1.2 percent of all sites), and Google (4.4 percent) as well as Windows. But if Microsoft continues to gain share at its current pace, it could close the gap on Apache sometime in 2008."
However, the situation might not be as bad as it seems for Apache. Over four per cent of sites surveyed used Google Web Server, which uses Apache code.
The survey examined the engines behind 127,961,479 websites around the world.
Apache market share slips below 50 percent
By Iain Thomson on Aug 8, 2007 2:17PM