This is yet another upcoming story for open source software. According to IDC:
Sales of open source software will grow from $1.8bn last year to $5.8bn in 2011. Matt Lawton, programme director for IDC's Open Source Software Business Models research programme, typified the current market as "immature" and in the "early stages".
The projected revenue figure is low when compared to commercial, closed source software. But the analyst believes that revenues alone do not reflect the actual distribution of open source software.