<p>Yaffs is available free of charge under the <a href="http://www.gnu.org/copyleft/gpl.html" target="_self" title="Gnu Public Licence">GNU General Public Licence,</a> version 2. This free version comes with the obligation on the User to provide (access to) Source Code to anyone who uses their products. If you do not wish to disclose your Source Code to all your customers you can buy a Licence from Aleph One Ltd which is like the usual Software licence in not requiring you to disclose Source Code.&nbsp; An example of our typical Licence, which is for one product, is given <a href="/node/32" target="_blank" title="Licence details">here.</a></p><p>Circumstances where you need to licence Yaffs other than under the GPL include:-</p><ul><li>If you want to run a statically-linked commercial RTOS on top of a Yaffs filesystem</li><li>if you want to sublicence Yaffs to your customers (under terms other than the GPL)</li><li>If you want to use Yaffs with WindowsCE version 4.&nbsp; WinCE version 3 can use GPL code but WinCE v.4 and later need an additional filesystem interface layer which is not part of Yaffs. This is available at extra cost; please contact us.</li></ul><p>While Yaffs is released under GPL we can provide standard support options, consulting in its application to your particular product, or development of specific features to suit your needs or hardware. Paid Licences are available in certain circumstances, for example Licences to redistribute Yaffs to your customers. The price is a matter of negotiation.</p><p>If you aren't sure whether your needs will be covered by the GPL version, <a href="/contact">get in touch with us</a>.</p><p>Access to the free GPL code is through <a href="/using-git" title="CVS use">our Git server</a>.</p><p>Although the code is downloadable at no charge, buying this product allows you to express your appreciation of Yaffs. Alternatively you can make a Donation to Aleph One Ltd via PayPal. You can do this at <a href="http://www.paypal.com" target="_blank" title="PayPal">PayPal </a>by sending any sum to sales@aleph1.co.uk&nbsp; We shall appreciate it!</p>