How to update ACAD file without having ACAD

[phives]

I have previuosly written a VB app that used a DLL called DWGMINER that allowed the manipulation of ACAD files directly without having to use ACAD itself.

Unfortunately this DLL is not updated for versions beyond 2008.

So my question is:

Is there a DLL or something that will work with later version of ACAD. I've seen REALDWG but it is crazy expensive.

[khoa.ho]

I am working with both CadLib from WoutWare and RealDWG. CadLib is the best non-Autodesk .NET library for AutoCAD. CadLib is pure .NET multi-threaded that beats over super heavy single-threaded RealDWG library. However, CadLib is still missing some minor features from official RealDWG. But so far, it is a very good commercial library.

RealDWG is a real pain to work on the web comparing to AutoCAD .NET API that works only on a single AutoCAD application.

Teigha.NET from Open Design Alliance is very similar to RealDWG, I can say almost 100% code in RealDWG can be used in Teigha.NET. This library is a wrapper of C++ code like ObjectARX.

CAD Import .NET from CadSoftTools is another good library but it does not support to save DWG format, just only read DWG.

There are some open source libraries that works on DXF format (not DWG) in Java, C++, C# code but most of them are not up-to-date. I also have my own incomplete DXF library in JavaScript at GitHub. So far commercial libraries are still good choices.

-Khoa