Exhibit 21.1

SUBSIDIARIES OF QUEST SOFTWARE, INC.



|                                            |  |                             
|------------------------------------------- |  | ----------------------------
|Name                                        |  | Jurisdiction Of Organization
|1397639 Ontario Ltd.                        |  | Ontario, Canada             
|881229 Alberta Ltd.                         |  | Alberta, Canada             
|Fastlane Technologies (UK) Limited          |  | United Kingdom              
|Fastlane Technologies Corporation           |  | Delaware                    
|Fastlane Technologies GmbH                  |  | Germany                     
|Active Concepts Pty, Ltd.                   |  | Australia                   
|Active Concepts, Inc.                       |  | California                  
|Fresh Dew Investments Limited               |  | British Virgin Islands      
|Murecia Investments Limited                 |  | British Virgin Islands      
|Quest Software France SARL                  |  | France                      
|Quest Software (UK) Ltd.                    |  | United Kingdom              
|Quest Software Pty., Ltd.                   |  | Australia                   
|Q.S.I. Quest Software Israel Limited        |  | Israel                      
|Quest Software Company Limited              |  | Ireland                     
|Quest Software International Limited        |  | Ireland                     
|Quest Software GmbH                         |  | Germany                     
|Quest Holding Company, LLC                  |  | California                  
|Quest Softair, Inc.                         |  | California                  
|Quest Software, Ltda                        |  | Brazil                      
|Quest Software Espana, S.A.                 |  | Spain                       
|Quest Software Mexico S. de R.L. de C.V.    |  | Mexico                      
|Quest Software Nederland B.V.               |  | Netherlands                 
|Quest Norge AS                              |  | Norway                      
|Quest Scandinavia AS                        |  | Denmark                     
|QSFT Svenska AB                             |  | Sweden                      
|Quest Software Switzerland Gmbh             |  | Switzerland                 
|Quest Software Belgium                      |  | Belgium                     
|Sitraka Corporation                         |  | Minnesota                   
|Quest Software Java Support Centre B.V.     |  | Netherlands                 
|Sitraka Deutschland GmbH                    |  | Germany                     
|Safari Limited Partnership                  |  | Canada                      
|Quest Software Canada                       |  | Canada                      
|eCritical Corporation                       |  | California                  
|QSI Development Corp.                       |  | Delaware                    
|Quest Acquisition Corp.                     |  | California                  
|Quest Software K.K.                         |  | Japan                       
|Quest Software Sales Sdn Bhd                |  | Malaysia                    
|Quest Software Singapore Ptd LTD            |  | Singapore                   
|Quest Software Limited                      |  | Hong Kong                   
|Quest Software Korea LTD                    |  | Korea                       
|QSFT India Private Limited                  |  | India                       
|Aelita Software Corporation                 |  | Delaware                    
|Aelita Software Limited                     |  | United Kingdom              
|IRSM, Inc.                                  |  | Ohio                        
|Lecco Canada                                |  | Canada                      
|Lecco Technology (UK) Limited               |  | United Kingdom              
|Lecco Technology (USA), Inc.                |  | Delaware                    
|Quest Software Italia  S.R.L. Unipersonale |  | Italy                       
|Quest Software Greater China Limited        |  | Hong Kong                   



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|                                       |  |                             
|-------------------------------------- |  | ----------------------------
|Name                                   |  | Jurisdiction Of Organization
|Quest Software Beijing Company Limited |  | China                       
|Quest Software (Zhuhai) Limited        |  | China                       
|Quest Software Public Sector, Inc.     |  | Delaware                    
|Vintela, Inc.                          |  | Utah                        
|Vintela Pty. Ltd.                      |  | Australia                   
|Vintela Australia Pty. Ltd.            |  | Australia                   
|Wedgetail Communications Incorporated  |  | Delaware                    
|Imceda Software, Inc.                  |  | Delaware                    
|Imceda Technologies Pty. Ltd.          |  | Australia                   
|Imceda Software Australia Pty. Ltd.    |  | Australia                   
|DB Associates IT Pty. Ltd.             |  | Australia                   
|Wingra Technologies, LLC               |  | Wisconsin                   
|Quest Software New Zealand Limited     |  | New Zealand                 
|Charonware s.r.o.                      |  | Czech Republic              
|Magnum Technologies, Inc.              |  | Minnesota                   
|Invirtus, Inc.                         |  | Delaware                    
|ScriptLogic Corporation                |  | Delaware                    
|ScriptLogic UK Ltd.                    |  | United Kingdom              
|ScriptLogic Australia Pty. Ltd.        |  | Australia                   
|Vizioncore, Inc.                       |  | Illinois                    
|PassGo Technologies Ltd.               |  | United Kingdom              
|PassGo Technologies Trustees Ltd.      |  | United Kingdom              
|VirtualFabrix, Inc.                    |  | California                  
|NetPro Computing, Inc.                 |  | Delaware                    
|NetPro Europe, Inc.                    |  | Arizona                     
|NetPro Engineering, Inc.               |  | Arizona                     
|NetPro Computing France, Inc.          |  | Arizona                     
|NetPro Computing Canada, Inc.          |  | Arizona                     
|NetPro Computing Germany, Inc.         |  | Arizona                     
|NetPro Computing UK, Inc.              |  | Arizona