Matthew Aslett, July 12, 2010 @ 7:00 am ET

Venture capital funding for open source software-related vendors increased 11.5% in the second quarter, the third consecutive quarter of positive growth following a 6% rise in 4Q09 and a 38% increase in 1Q10.

According to our preliminary figures, OSS-related vendors raise $141.7m in Q2, compared to $127.1m a year ago. There were 21 deals in the quarter and 20 with a disclosed deal size, the same as 2Q09, resulting in an average deal size of $7.1m in 2Q10, compared with $6.4m in 2Q09.

Early stage deals announced in the quarter included $5m for Karmasphere and $2.5m for Datameer, both building businesses around Hadoop, as well as $7.15m forMoodlerooms, $14m for Sencha, $4m for AlienVault and an additional $3.3m for Nuxeo.

Later stage deals included $11m each for Cloud.com and Opscode, $10m each forHeroku, DeviceVM and Northscale, $9m for Zend, and $8m for Talend.

The biggest round announced in the quarter was Eucalyptus’s $20m series B round, which was reported just hours before the end of the quarter, tipping the total into positive growth.

Total funding for the first half of the year stands at $231.2, up from $191.7m in the first half of 2009. While it seems likely that we could see an overall improvement f