such information in confidence at the time of receipt of the information; (c) is properly obtained hereafter from a source that is not under an obligation of confidentiality with respect to such information; or (d) is developed independently by the Receiving Party without reference to or use of the Disclosing Party's Confidential Information. 6.4.2 Non-Disclosure. Neither Party shall use or disclose Confidential Information of the other Party to any third party, without the written consent of the Disclosing Party of such Confidential Information. Receiving Party agrees to undertake reasonable measures to maintain and preserve the Confidential Information of the Disclosing Party in confidence, which measures shall be no less than the measures taken by the Receiving Party to protect its own confidential information and in no vent shall be less than reasonable care. Upon expiration or termination of this Agreement, Receiving Party will immediately destroy or erase all copies of documents or materials containing any Confidential Information provided by Disclosing Party and, upon the Disclosing Party's request, promptly confirm destruction of same by signing and returning to the Disclosing Party a certificate of destruction reasonably satisfactory to the Disclosing Party. 6.4.3 Derivatives. All Confidential Information, and any Derivatives thereof whether created by Client or Developer, remain the property of the Disclosing Party and no license or other rights to any Confidential Information or Derivatives is granted or implied hereby. For purposes of this Agreement, Derivatives shall mean: (a) for copyrightable or copyrighted material, any translation, abridgment, revision or other form in which an existing work may be recast, transformed or adapted ;(b) for patentable or patented material, any improvement thereon; and (c) for material which is protected by trade secret, any new material derived from such existing trade secret material, including new material which may be protected under applicable copyright,