Red Hat ( RHAT) was among the tech sector's biggest losers Wednesday, with shares tumbling 23% after the Linux software developer's revenue forecast for the current quarter missed expectations. For the second quarter ended Aug. 31, the company earned $11 million, or 5 cents a share, on revenue of $99.7 million. Excluding items, earnings were $23.7 million, or 11 cents a share. Analysts polled by Thomson First Call expected earnings of 10 cents a share, before items, on revenue of $97.1 million. A year ago, Red Hat posted adjusted second-quarter earnings of $17.7 million, or 9 cents a share, on revenue of $65.7 million. Red Hat forecast third-quarter earnings of 12 cents to 13 cents a share, compared with analysts' average projection of 12 cents. But the company predicted revenue of $103.5 million to $105 million, below Wall Street's expectation of $105.7 million. The stock was trading down $6.11 to $20.21 on volume of more than 46 million shares. Shares of Jabil Circuit ( JBL) rose 6% after the electronics-manufacturing services company reported revenue that beat expectations. For the period ended Aug. 31, the company had revenue of $3.0 billion, up from $2.0 billion a year earlier. Analysts expected revenue of $2.84 billion. Jabil didn't report its bottom-line results because the company is continuing to probe its historical stock options practices. Jabil anticipates first-quarter revenue of $3.1 billion to $3.3 billion. Analysts project revenue of $3.07 billion. Shares were trading up $1.57 to $29.46.