Shares of open source software specialist Red Hat ( RHT) rose in extended trading Wednesday after the firm saw its fourth-quarter revenue grow almost 20%. The firm's reported revenue of $166.2 million, an increase of 18% from the year-ago quarter and roughly in line with analysts' estimate of $166.99 million. Revenue from software subscription drove Red Hat's growth, growing 14% year over year to $139.4 million. Investors responded positively to the results, and Red Hat's shares rose 60 cents, or 4%, to $15.60, in after-hours trading. "Our value proposition is even more compelling in a challenging economic environment, and we believe that's a key driver to our solid financial results and market share gains," said Jim Whitehurst, the Red Hat CEO, in a statement. Red Hat's profit, however, fell year-over-year. The company reported earnings of 8 cents a share on net income of $16 million, compared to earnings of 10 cents a share and net income of $22 million in the prior year's quarter. Excluding charges, Red Hat earned 22 cents a share on net income of $42.3 million, compared to 21 cents and $45.7 million in the same period last year. Analysts had estimated earnings of 20 cents a share. For the full year, Red Hat's total revenue was $652.6 million, an increase of 25% over the prior year, but just below analysts' estimate of $653.64 million. Shares of the Linux specialist climbed steeply then tumbled earlier this week following speculation that Red Hat could become an Oracle ( ORCL) acquisition target.