Hi paoki, yeah the script that Burr shows there is the one that you can use to select/highlight edges that are not joined, that should show you what spots are open on a joined surface that are preventing it from being a closed solid.

At the moment there is nothing similar available for curves, but I will add in a method for the next v2 beta so that a script will be able to mark the start/end point of open curves with a point object, that should help to make it possible to set up a keyboard shortcut that will mark those areas for you on curves.

In the future I do want to have some more convenient ways to display these things, like there will probably be something under the "View" palette for displaying naked/unjoined edges in a certain color but I'm not quite sure when that one will happen.

But for now that select script will get the job done for surfaces, and with the next beta it will be possible to have a similar one for curves.

- Michael