> Isn't it true that, with .n, a single link change will require the entire .n > file (with "tons" of nodes) to rewritten while, with .def, only one small file > will have to be rewritten? It is true that the whole .n will have to be rewritten. However, I've been dealing with .n files of more than 50 nodes and the save operation is done instantly. I believe you could save a .n with 200 nodes in no more time than it takes to save a Word Document. Also, from my experience, you aren't likely to use networks of more than 50-100 nodes. At that point the "program" simply gets too hard to read. Past that, the simplest to to is to break the .n into "functions" in different .n files... the same way as you split a C program into multiple .c files. There's also another thing I'd like to say about the .n format in Overflow. Unlike Piper, for which (if I'm correct) the in-memory storage went after the permanent storage, the ideas between Overflow were the other way (is that correct english?). When I wrote the permanent storage, I used XML simply because I had a library that was doing all the work for me. I did not care what the .n would look like. The fact that I could save and load was enough for me. This is all to say that for me, the permanent storage is just a "nice feature to have" that allows you to keep your work, but it's nothing fundamental in the system. Jean-Marc -- Jean-Marc Valin Universite de Sherbrooke - Genie Electrique valj01 at gel.usherb.ca