So what are these things that LOL tries to install

[Phoenix-D]

?

Ok, I've got a decent idea of what the .net framework is, but I've never heard of "managed directX" and no game I've used has used it except LOL..

[Richard]

It's fairly new but for those techie folks out there I found this:

Managed DirectX is the new core technology added to the DirectX API. It requires both Visual Studio .NET and the .NET framework for development. By eliminating the COM interop layer it enhances performance over previous typelibs. For example, the performance goal for Managed Direct3D is 98% of core C++ performance. By using managed code, there is a minimum reduction in code of 10% and upwards of 40% in some cases. Managed code is a great productivity improvement and frees developers from having to deal with memory management tasks. It enables Visual Studio .NET developers to have easy access to the DirectX APIs through managed code. They can now take advantage of the multimedia functionality and hardware acceleration of DirectX. The following are the main features of Managed DirectX

Full support for all of the features in Direct3D, D3DX, DirectDraw, DirectPlay, DirectInput, and DirectSound.
Support for simple playback of many common audio and video formats.
A near 1 for 1 complement of samples when compared with C++.
Code reduction: Most common tasks done in DirectX are done with fewer lines of code via Managed Code.
Tight integration with .NET - Managed DirectX fully utilizes .NET and it's common types anywhere it can.
A Managed DirectX Application Wizard

[Hiro_Antagonist]

In a nutshell, Managed DirectX is simply DirectX for .NET.

If an app uses .NET (as LOL does) and it uses DirectX (like most Windows games do), then the game needs to use Managed DirectX.

.NET and Managed DirectX are still pretty rare in game development. To my knowledge there are only 2 commercial games/series that used them before. One is the Tin Soldiers series, which uses .NET and MDX. The other is a game called Arena Wars, which uses .NET but does not use MDX. NASA also has an open source product called "World Wind" which uses .NET and MDX. (In fact, we leveraged the install scripts from that NASA project for LOL.)

Managed DirectX is just a set of wrapper DLLs that are used to allow managed code (.NET) to use standard DirectX functionality. It will not interfere with normal DirectX at all -- it fact, it requires normal DirectX to be installed because it uses it too.

Both .NET and Managed DirectX are developed and fully vouched for by Microsoft. They are encouraging developers to use it, and we're one of the first. .NET and MDX will both be included in Longhorn/Vista, the next version of Windows, which will prevent the annoying extra install step for .NET games on that OS.

-Hiro_Antagonist