Dear all, I am trying to us \useURL and \from with mixed success to access a local file so that it will be opened by a helper program. Both the program and the file to be opened by it reside in my local file system. Here is a small example: \setupcolors[state=start] \setupinteraction [state=start,color=blue] \useURL[cycloids][{file://3dxm/cycloids.stng}][][3DXM] \starttext \inmargin{\from[cycloids]} In this section, we study curves that are obtained by tracing a point on a fixed circle while it is rolling along another circle. \stoptext cycloids.stng is a file, that, when double-clicked, starts a program it is associated with. For trying, you can replace it by any other file that uses a special application to go with. Unfortunately, this *only* works with the pdf viewer in TeXShop (I am on a Mac). Preview doesn't do anything but beep, and Acrobat 6 offers a few choices, none of which is to open a helper application. Does anybody know if there is another way of launching helper applications when accessing documents? Also, while at it: When accessing local files, the URL appears to be absolute. Is there a way to use URLs relative to the location of the PDF that is referencing the URL? Thanks, Matthias