Employee Equity Incentive Plans (Tables)

6 Months Ended

Mar. 31, 2013

Employee Equity Incentive Plans [Abstract]

Summary of stock options outstanding and changes

	Number of Shares			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (In Years)		Aggregate Intrinsic Value
Outstanding, September 30, 2012		8,142,468		$	2.67
Granted		1,859,107		$	2.64
Exercised		(389,781	)	$	1.39
Forfeited		(187,091	)	$	3.37
Outstanding March 31, 2013		9,424,703		$	2.71		7.6	$	5,313,772
Vested and expected to vest in the future, March 31, 2013		9,072,526		$	2.71		7.5	$	5,218,502
Exercisable, March 31, 2013		4,346,368		$	2.68		6.5	$	3,696,086

Assumptions used in the Black-Scholes model for options granted

Expected volatility	83%-84%
Expected term in years	5.4
Expected risk-free interest rate (zero coupon U.S. Treasury Note)	0.8%-0.9%
Expected dividend yield	0%

Summary of RSU activity

	Number of Shares			Weighted Average Grant Date Fair Value
Unvested, September 30, 2012		1,016,624		$	2.23
Granted		1,166,301		$	2.65
Vested		(237,335	)	$	3.07
Forfeited		(21,297	)	$	2.24
Unvested, March 31, 2013		1,924,293		$	2.38