Exhibit 99.1

Press Contact: Holly Lawrence TIBCO Software Inc. (650) 846-8463 hlawrenc@tibco.com	Investor Relations Contact: Michael Magaro TIBCO Software Inc. (650) 846-5747 mmagaro@tibco.com

TIBCO SOFTWARE REPORTS

RECORD FOURTH QUARTER AND ANNUAL

FINANCIAL RESULTS;

ANNOUNCES STOCK REPURCHASE PROGRAM

PALO ALTO, Calif., December 21, 2005 – TIBCO Software Inc. (Nasdaq:TIBX), a leading business integration and process management software company that enables real-time business, today announced results for its fourth fiscal quarter and year ended November 30, 2005. Total revenues for the fourth quarter were $134.4 million. License revenues for the fourth quarter were $66.8 million. Fiscal year 2005 revenues were $445.9 million. Net income for the quarter calculated in accordance with generally accepted accounting principles was $26.6 million or $0.12 per share on a fully diluted basis.

TIBCO had non-GAAP net income for the fourth fiscal quarter of $21.8 million and $53.3 million for the year. TIBCO’s non-GAAP net income per share on a fully diluted basis was $0.10 per share for the quarter and $0.24 for the year. Non-GAAP results exclude stock-based compensation charges, restructuring charges and amortization of acquired intangibles and assume a non-GAAP effective tax rate of 38%.

“With a record quarter of revenue, we have given a strong finish to the year and created good momentum for Fiscal 2006,” said Vivek Ranadivé, Chairman and CEO of TIBCO Software. “I believe the current strength and leadership of our products in the areas of SOA, BPM and Predictive Analytics, coupled with our continued focus on their evolution, positions us well to take advantage of the growing importance of and opportunity for infrastructure software.”

Highlights for TIBCO’s Fourth Fiscal Quarter of 2005

During Q4, TIBCO added 89 new customers and made significant sales to both new and existing customers, including Union Pacific Railroad, Embratel Group, Seagate Technology, Inc., Harvard Pilgrim Health Care and Allstate Insurance Company.

Stock Repurchase Program

TIBCO’s Board of Directors has approved an eighteen-month stock repurchase program pursuant to which TIBCO may repurchase up to $100 million of its outstanding common stock from time to time on the open market or through privately negotiated transactions. The timing and amount of any repurchases will depend upon market conditions and other corporate considerations.

Conference Call Details

TIBCO Software has scheduled a conference call for 5:00 p.m. Eastern Time today to discuss its fourth fiscal quarter results. The conference call will be hosted by CCBN and may be accessed over the Internet at http://www.tibco.com or via dial-in at (800) 500-0177 or (719) 457-2679. Please join the conference call at least 10 minutes early to register. A replay of the conference call will be available through midnight on January 21, 2005 at www.tibco.com or via dial-in at (888) 203-1112 or (719) 457-0820. The pass code for both the call and the replay is 8328748.

About TIBCO Software

TIBCO Software Inc. (NASDAQ:TIBX) is a leading business integration and process management software company that enables real-time business. Real-Time Business is about helping companies become more cost-effective, more agile and more efficient. TIBCO has delivered the value of Real-Time Business, what TIBCO calls The Power of Now^®, to over 2,000 customers around the world and in a wide variety of industries. For more information on TIBCO’s proven enterprise backbone, business integration, business process management, and business optimization solutions, TIBCO can be reached at +1 650-846-1000 or on the Web at www.tibco.com. TIBCO is headquartered in Palo Alto, CA.

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TIBCO, the TIBCO logo, The Power of Now and TIBCO Software are trademarks or registered trademarks of TIBCO Software Inc. in the United States and/or other countries. All other product and company names and marks mentioned in this document are the property of their respective owners and are mentioned for identification purposes only.

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Use of Non-GAAP Financial Information

TIBCO provides non-GAAP net income and net income per share data as additional measures of its operating results. TIBCO believes that non-GAAP financial measures of income provide useful information to management and investors regarding certain additional financial and business trends relating to the company’s financial condition and results of operations. For example, the non-GAAP results are an indication of TIBCO’s baseline performance before gains, losses or other charges that are considered by management to be outside the company’s core business operational results. In addition, these non-GAAP results are among the primary indicators management uses as a basis for planning for and forecasting of future periods. These measures are not in accordance with, or an alternative for, generally accepted accounting principles in the United States and may be different from non-GAAP measures used by other companies.

Legal Notice Regarding Forward-Looking Statements

This release contains forward-looking statements within the meaning of the “safe harbor” provisions of the federal securities laws, including, without limitation, statements regarding the momentum in TIBCO’s business and TIBCO’s ability to take advantage of future opportunities in the infrastructure software market. Actual results could differ materially from such forward-looking statements if demand for integration software or economic conditions affecting the market for integration software fluctuate or if TIBCO is unable to compete successfully with new or existing competitors. In addition, TIBCO’s intentions with regard to the stock repurchase program may be affected by a number of factors which include the market price of TIBCO’s stock, general business and market conditions, and management’s determination of alternative needs and uses of TIBCO’s cash resources. Additional information regarding potential risks is provided in TIBCO’s filings with the SEC, including its most recent Annual Report on Form 10-K for the year ended November 30, 2004 and Quarterly Report on Form 10-Q for the quarter ended August 28, 2005. TIBCO assumes no obligation to update the forward-looking statements included in this release.

TIBCO Software Inc.

Non-GAAP Consolidated Statements of Operations

Impact of Non-GAAP Adjustments on Reported Net Income

(Unaudited)

(in thousands, except per share data)

	Three Months ended November 30, 2005							Year ended November 30, 2005
	GAAP		Adjustments (1)			Non-GAAP As Adjusted		GAAP			Adjustments (1)			Non-GAAP As Adjusted
Revenue	$	134,431	$	—		$	134,431	$	445,910		$	—		$	445,910
Cost of revenue		34,186		(1,330	)		32,856		124,193			(5,973	)		118,220
Gross profit		100,245		1,330			101,575		321,717			5,973			327,690
Operating expenses:
Research and development		21,604		—			21,604		73,136			(9	)		73,127
Sales and marketing		36,683		(19	)		36,664		140,370			(104	)		140,266
General and administrative		10,051		—			10,051		37,320			(1	)		37,319
Restructuring charges		—		—			—		3,905			(3,905	)		—
Amortization of acquired intangibles		2,397		(2,397	)		—		8,912			(8,912	)		—
Total operating expenses		70,735		(2,416	)		68,319		263,643			(12,931	)		250,712
Income from operations		29,510		3,746			33,256		58,074			18,904			76,978
Interest and other income, net		1,898		—			1,898		9,007			—			9,007
Income before income taxes		31,408		3,746			35,154		67,081			18,904			85,985
Provision for (benefit from) income taxes (2)		4,821		8,538			13,359		(5,474	)		38,148			32,674
Net income	$	26,587	$	(4,792	)	$	21,795	$	72,555		$	(19,244	)	$	53,311
Net income per share - Basic	$	0.13				$	0.10	$	0.34					$	0.25
Shares used to compute net income per share - Basic		211,444					211,444		213,263						213,263
Net income per share - Diluted	$	0.12				$	0.10	$	0.32					$	0.24
Shares used to compute net income per share - Diluted		220,513					220,513		223,977						223,977

⁽¹⁾ The following table summarizes the adjustments presented:

	Three Months ended November 30, 2005			Year ended November 30, 2005
Net income, GAAP	$	26,587		$	72,555
Stock-based compensation		19			129
Amortization of acquired intangibles		3,727			14,870
Restructuring charges		—			3,905
Provision for income taxes		(8,538	)		(38,148	)
Net income, non-GAAP	$	21,795		$	53,311

⁽²⁾ The estimated non-GAAP effective tax rate for 2005 of 38% has been used to adjust the provision for income taxes for non-GAAP purposes.

TIBCO Software Inc.

Consolidated Statements of Operations

(Unaudited)

(in thousands, except per share data)

	Three Months ended						Year ended
	November 30, 2005			November 30, 2004			November 30, 2005			November 30, 2004
Revenue:
License revenue:
Non-related parties	$	66,753		$	66,336		$	187,850		$	197,753
Related parties		—			4,214			16,038			16,333
Total license revenue		66,753			70,550			203,888			214,086
Service and maintenance revenue:
Non-related parties		64,457			50,599			228,539			155,864
Related parties		1,233			2,996			6,973			12,692
Reimbursable expenses		1,988			1,514			6,510			4,578
Total service and maintenance revenue		67,678			55,109			242,022			173,134
Total revenue		134,431			125,659			445,910			387,220
Cost of revenue:
Cost of license		3,542			3,940			12,694			11,587
Cost of service and maintenance		30,644			26,761			111,499			81,610
Total cost of revenue		34,186			30,701			124,193			93,197
Gross Profit		100,245			94,958			321,717			294,023
Operating expenses:
Research and development		21,604			17,954			73,136			61,100
Sales and marketing		36,683			36,997			140,370			123,486
General and administrative		10,051			9,767			37,320			29,048
Acquired in-process research & development		—			—			—			2,200
Restructuring charges		—			2,186			3,905			2,186
Amortization of acquired intangibles		2,397			2,053			8,912			5,253
Total operating expenses		70,735			68,957			263,643			223,273
Income from operations		29,510			26,001			58,074			70,750
Interest income		3,786			2,310			13,318			8,436
Interest expense		(671	)		(693	)		(2,711	)		(2,771	)
Other income (expense), net		(1,217	)		(1,086	)		(1,600	)		(2,700	)
Income before income taxes		31,408			26,532			67,081			73,715
Provision for (benefit from) income taxes		4,821			8,308			(5,474	)		28,795
Net income	$	26,587		$	18,224		$	72,555		$	44,920
Net income per share - Basic	$	0.13		$	0.09		$	0.34		$	0.22
Shares used to compute net income per share - Basic		211,444			212,432			213,263			207,506
Net income per share - Diluted	$	0.12		$	0.08		$	0.32		$	0.20
Shares used to compute net income per share - Diluted		220,513			227,628			223,977			220,927

TIBCO Software Inc.

Consolidated Balance Sheets

(Unaudited)

(in thousands)

	November 30, 2005		November 30, 2004
ASSETS
Current assets:
Cash and cash equivalents	$	208,756	$	180,849
Short-term investments		268,882		292,686
Accounts receivable, net		121,159		109,002
Accounts receivable from related parties		1,243		2,886
Other current assets		18,111		16,984
Total current assets		618,151		602,407
Property and equipment, net		116,457		118,058
Long-term deferred income tax assets		27,440		—
Other assets		34,559		32,389
Goodwill		261,075		265,137
Acquired intangibles, net		64,742		64,820
Total assets	$	1,122,424	$	1,082,811
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	9,656	$	7,058
Accrued liabilities		59,872		84,429
Accrued restructuring and excess facilities costs		6,390		9,489
Deferred revenue		82,300		60,633
Current portion of long-term debt		1,798		1,708
Total current liabilities		160,016		163,317
Accrued excess facilities costs, less current portion		23,599		29,878
Long-term deferred income tax liabilities		13,875		18,991
Long-term debt, less current portion		48,345		50,143
Other long-term liabilities		2,970		—
Total liabilities		248,805		262,329
Total stockholders’ equity		873,619		820,482
Total liabilities and stockholders’ equity	$	1,122,424	$	1,082,811

TIBCO Software Inc.

Consolidated Statements of Cash Flows

(Unaudited)

(in thousands)

	Year ended
	November 30, 2005			November 30, 2004
Cash flows from operating activities:
Net income	$	72,555		$	44,920
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property and equipment		14,990			13,152
Amortization of acquired intangibles		14,870			11,955
Loss on disposal of property and equipment		109			—
Write-off in-process research and development		—			2,200
Stock-based compensation		129			236
Realized loss on investments, net		275			402
Deferred income tax		(21,893	)		666
Tax benefits related to acquisitions		1,149			4,315
Tax benefits related to stock options		15,851			6,006
Changes in assets and liabilities:
Accounts receivable		(8,764	)		(36,817	)
Accounts receivable from related parties		1,643			(73	)
Other assets		(2,853	)		4,410
Accounts payable		2,774			1,315
Accrued liabilities, restructuring and excess facilities costs		(26,823	)		16,461
Deferred revenue		18,816			5,592
Net cash provided by operating activities		82,828			74,740
Cash flows from investing activities:
Purchases of short-term investments		(231,489	)		(530,754	)
Sales and maturities of short-term investments		254,917			757,085
Cash used in acquisition, net of cash received		(24,849	)		(115,009	)
Purchases of property and equipment, net		(14,946	)		(7,101	)
Purchases of private equity investments		(382	)		(454	)
Restricted cash and short-term investments pledged as security		(465	)		4,565
Net cash provided by (used for) investing activities		(17,214	)		108,332
Cash flows from financing activities:
Proceeds from exercise of stock options		13,559			24,452
Proceeds from employee stock purchase program		4,042			5,047
Repurchase of the Company’s common stock		(48,300	)		(115,702	)
Principal payments on long term debt		(1,708	)		(1,626	)
Net cash used for financing activities		(32,407	)		(87,829	)
Effect of exchange rate changes on cash		(5,300	)		2,328
Net change in cash and cash equivalents		27,907			97,571
Cash and cash equivalents at beginning of year		180,849			83,278
Cash and cash equivalents at end of year	$	208,756		$	180,849