Is it possible to to integrate/communicate from a linux/Apache (PHP) web server to a CRM built around Microsoft Dynamics?
The example code I have is in C / C#, and assuming the web server is running on Microsoft - but I am using Linux/Apache and PHP. Can I still communicate and if so - how do I "interpret" the C# code to PHP?
You can do this using web services. The web services are best way to let different technologies communicate with each other.
There are two most popular formats, xml and json.
More information here:
http://www.w3schools.com/webservices/default.asp
http://msdn.microsoft.com/en-us/library/ms950421.aspx
Some question specific resources:
C# + PHP in the same application?
There is also a php compiler available for c#.
http://www.php-compiler.net/blog/2011/php-code-c-sharp
Hope this helps. Let me know if any more information required.