Yes. One licence per website. If you buy it and don't use it; you can simply assign it to another website.

Here is the full licence terms from Concrete5-


In English
You own your copy for use on one (1) site and the development environment for it. Use it on another site, you should buy it again. Don't sue us.

In Legal
concrete CMS Inc is herein referred to as DEVELOPMENT PARTNER.

This License (“the Agreement”) is between DEVELOPMENT PARTNER and Customer as identified on the Order Details Email. This Agreement applies to all employees in Customer’s organization (“Authorized Users”).

1. License Grant. Subject to the provisions of this Agreement, Customer is granted a limited, non-transferable, non-exclusive license to use the Software Application for a single website and a single staging or development version. Customer may not offer the System for resale without expressed permission from DEVELOPMENT PARTNER.

2. Augmenting Code. Customer may modify, supplement, adapt, translate or create derivative works based upon the System. Any modifications are fully owned by customer, and do not effect the license limitations for further use. Customer shall have no right to copy the System without DEVELOPMENT PARTNER’s prior written consent, which may be withheld for any reason.

3. Ownership. The System is licensed, not sold. Customer acknowledges that the System (including any changes Customer may request or suggest) is the property of DEVELOPMENT PARTNER or its licensors. Title to the System and all related intellectual property will remain with DEVELOPMENT PARTNER and its licensors at all times, as will all other rights not explicitly granted to Customer in this Agreement.

4. Important Warranty Disclaimers and Limitation of Liability.

NO WARRANTY. Although DEVELOPMENT PARTNER attempts to deliver accurate, complete content and error-free software applications, occasional errors or omissions may occur in the System. EXCEPT AS SPECIFICALLY PROVIDED IN THIS AGREEMENT, THE SYSTEM IS PROVIDED "AS IS." DEVELOPMENT PARTNER MAKES NO OTHER REPRESENTATION OR WARRANTY, EITHER EXPRESS OR IMPLIED. DEVELOPMENT PARTNER DOES NOT WARRANT THE ACCURACY, COMPLETENESS, PERFORMANCE, CURRENCY, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE OF THE SYSTEM. DEVELOPMENT PARTNER DISCLAIMS ALL RESPONSIBILITY FOR ANY LOSS OR CLAIM OF ANY KIND RESULTING FROM, ARISING OUT OF, OR ANY WAY RELATED TO USE OF THE SYSTEM. DEVELOPMENT PARTNER’S ENTIRE LIABILITY AND OBLIGATION SHALL BE LIMITED TO DEVELOPMENT PARTNER USING COMMERCIALLY REASONABLE EFFORTS TO CORRECT ERRORS OR OMISSIONS AND SHALL CONSTITUTE CUSTOMER’S SOLE RIGHT AND EXCLUSIVE REMEDY HEREUNDER WITH REPECT TO THE SYSTEM.

IMPORTANT LIMITATION OF LIABILITY. IN NO EVENT SHALL DEVELOPMENT PARTNER OR ITS OFFICERS, EMPLOYEES, VENDORS OR LICENSORS BE LIABLE FOR LOSS OF DATA, LOSS OF PROFIT, OR FOR ANY OTHER SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGES, HOWEVER CAUSED, WHETHER BASED UPON CONTRACT, NEGLIGENCE, STRICT LIABILITY IN TORT, WARRANTY, OR ANY OTHER LEGAL THEORY. IN NO EVENT SHALL DEVELOPMENT PARTNER’S CUMULATIVE AGGREGATE LIABILITY UNDER THIS AGREEMENT EXCEED THE TOTAL FEES PAID BY CUSTOMER TO DEVELOPMENT PARTNER WITH RESPECT TO THE THEN-CURRENT TERM OF THE AGREEMENT.


5. U.S. Government Restricted Rights. All Developments provided hereunder are provided with RESTRICTED RIGHTS. Use, duplication, or disclosure by the U.S. Government is subject to restrictions as set forth in subparagraphs (c)(1) and (2) of the Commercial Computer Software - Restricted Rights at 48 CFR § 52.227-19, as applicable. Manufacturer is DEVELOPMENT PARTNER, [THEIR ADDRESS].

6. Export. In the event any product or service that is the subject of this Agreement is exported from the United States or exported/re-exported from a foreign destination by Customer, the Customer shall ensure that the distribution and export/re-export of that product or service is in compliance with all laws, regulations, orders, or other restrictions of the U.S. Export Administration Regulations. The Customer agrees that neither it nor any of its subsidiaries will export/re-export any technical data, process, product, or service directly or indirectly to any country for which the U.S. government or any agencies thereof requires an export license or other government approval without first obtaining such license or approval.

7. Miscellaneous.
♣ Entire Agreement. This document constitutes the entire Agreement between the parties and supersedes all prior or contemporaneous negotiations and agreements, whether written or oral. No modification or amendment to this Agreement, nor any waiver of any rights, will be effective unless assented to in writing by both parties, and the waiver of any breach or default will not constitute a waiver of any other right or any other breach or default. This Agreement may be amended only by a writing signed by both parties.
♣ Assignment. Customer may not assign any portion of this Agreement except with the prior written consent of DEVELOPMENT PARTNER, and any attempt to assign (by operation of law or otherwise) this Agreement or any part thereof without consent shall be null and void. However, DEVELOPMENT PARTNER shall not unreasonably withhold its consent to an assignment.
♣ Forum Selection and Choice of Law. This Agreement shall be governed by the laws of Oregon, without regard to its choice of law rules. By entering into this Agreement Customer agrees to be subject to personal jurisdiction in Oregon courts. Any litigation arising from or related to this Agreement shall be brought only in the federal or state courts in Multnomah County, Oregon.
♣ Attorneys Fees; Costs. In addition to any other relief, the prevailing party in any dispute arising under this Agreement will be entitled to all reasonable legal fees and costs.
♣ Performance. A party is not liable under this Agreement for non-performance, if the non-performance is caused by events or conditions beyond that party's control, and provided the party makes reasonable efforts to perform under the circumstances. The obligations and rights of the party so excused shall be extended on a day-to-day basis for the period of time equal to that of the underlying cause of the delay. This provision does not relieve Customer of its obligation to make any payments then owing.
♣ Severability. If any provision of this Agreement is held invalid or unenforceable, that portion shall be construed in a manner consistent with applicable law to reflect, as nearly as possible, the original intentions of the parties, and the remaining provisions shall not be affected.
♣ Headings. Section headings are for convenience only and shall have no substantive meaning.
♣ Survival. Provisions of this Agreement relating to warranties, intellectual property rights, limitation and exclusion of liability, indemnification, and payment obligations will survive the termination or expiration of this Agreement.

All code, documentation & license materials are Copyright 2012, DEVELOPMENT PARTNER