(PHP 4 >= 4.1.0, PHP 5, PHP 7)
The DOTNET class allows you to instantiate a class from a .Net assembly and call its methods and access its properties.
$obj = new DOTNET("assembly", "classname")
$assembly_name
   , string $class_name
   [, int $codepage
  ] )
   DOTNET class constructor.  assembly_name specifies
   which assembly should be loaded, and class_name
   specifices which class in that assembly to instantiate.  You may
   optionally specify a codepage to use for unicode
   string transformations; see the COM class
   for more details on code pages.
  
The returned object is an overloaded object, which means that PHP does not see any fixed methods as it does with regular classes; instead, any property or method accesses are passed through to COM and from there to DOTNET. In other words, the .Net object is mapped through the COM interoperability layer provided by the .Net runtime.
Once you have created a DOTNET object, PHP treats it identically to any other COM object; all the same rules apply.
Example #1 DOTNET example
<?php
 $stack = new DOTNET("mscorlib", "System.Collections.Stack");
 $stack->Push(".Net");
 $stack->Push("Hello ");
 echo $stack->Pop() . $stack->Pop();
?>
Note:
You need to install the .Net runtime on your web server to take advantage of this feature.