[[Property:title|Melting Ice Technology]]
[[Property:weight|-15]]
[[Property:uuid|17c5cf39-2bb3-67e4-11e3-2b6d021e5df1]]
EiffelStudio relies on Melting Ice Technology, the proprietary compilation mechanism of Eiffel Software, which offers three forms of compilation:
*  ''melting'' for making a few changes. The fastest of the mechanisms, typically taking a few seconds after small changes. Melting time is proportional to the size of the changed parts and affected classes, while the time needed to freeze or finalize is partly proportional to the size of the whole system. As long as you do not include new external C/C++ code, a C/C++ compiler is not required. However, execution speed is not optimal. The generated executable is debuggable. 
*  ''freezing'' generates C code from the active system, and then compiles it into machine code; you must have a C/C++ compiler installed. You need to use this option if you add new agents or external C/C++ calls. Unless you add external code, you can re-freeze every couple of days. The rest of the time, you can melt your software to receive immediate feedback. The speed is still slower than when finalizing, but the generated executable is still debuggable. 
*  ''finalizing'' delivers a production version (intermediate or final) of your software. It can be used to measure its performance in operational conditions. Finalization performs extensive time and space optimizations that enable Eiffel to match the efficiency of C/C++; it also creates a stand-alone C package that you can use for cross-platform development. Because of all the optimizations involved, finalizing takes the most time, and the generated executable is not debuggable. 

Melting and freezing generate an executable in the EIFGENs|target_name|W_code subdirectory of the project directory. The executable is composed of a standard executable file named after the system, and of a < ''system name''>.melted file, which is called the Eiffel update file. Although it is recommended to finalize the system when running it from outside EiffelStudio (since the performance is better), it is possible to launch a melted/frozen executable. However, the Eiffel update file is necessary, the executable alone will not run. 

Basically, the Eiffel update file incorporates the changes that have been made to the system since it was last frozen. Therefore, it is very small when the system has just been frozen, and progressively becomes bigger each time the system is melted. On the contrary, the executable is only modified when the system is frozen, never when it is melted.

The contents of the Eiffel update file are in a byte code representation which is dynamically interpreted at run-time.




