libticables2-7.dll is indeed the file name used by the TILP II 1.18 release train. But if it didn't exist / if its packaging had failed somehow, the InnoSetup wizard would have errored out on me...

The release notes weren't updated, that's all

Well, I'm really new to TILP, and I'm in need of a good linking program since TIconnect stopped working
I installed different versions several times (now the 1.18) but all show up not working in the same way. I get this Error on startup:
"Msg: illegal operation or argument. Cause: the program which uses this library is buggy. Fire-up the developer! System: (1990529472) file not found."
I click "close", then this shows up: "Msg: attempting to use a cable which has not been open before. Cause: Internal error."
I click "close" again. TiLP opens. Anything I try to do ends up with: "The cable cannot be used. Cause: the cable has not been initialized due to a previous/current error."

I'd be glad if someone could help me

Ok, forget to say that. It's Windows 7 64 bit, TI-83+ (1.19), SilverLink USB. And yes, TIconnect is installed. I'll try again

Edit: I unstilled Tilp and TIConnect, then reinstalled TILP. Still the same problem

These are the instructions from the README that I think Lionel is referring to:

It is possible to install TI-Connect(tm) / TI-Nspire Computer (Link) Software(tm)
and TILP side by side, but this requires a manual configuration.
The following steps assume that TI-Connect / TINC(L)S is already installed:
* download the filter driver installer and install it, using the instructions given at
  http://sourceforge.net/apps/trac/libusb-win32/wiki , section "Filter Driver Installation";
* launch the filter wizard (accessible from the new entry in the Start menu) when the
  device (SilverLink, 84+, 89T, 84+SE, Nspire) you want to use with both TILP and
  TI-Connect / TILP and (TINCLS or TINCS) is plugged *in*;
* install the filter driver for that particular device;
* run the TILP installer.
After that, the device ought to work in both TILP and TI-Connect / TILP and (TINCLS or TINCS).

Nearly 4 months later, here's a new build.

Main changes between the second TILP II 1.18 Windows beta build and this one:
* addition: near-complete German translation, contributed through Debian downstream (I don't speak German, so help needed for keeping the translation up to date)
* addition: two commands for sending and reading generic data in NavNet format from a Nspire, similar to TI's TI_NN_Write and TI_NN_Read. They shall be useful for e.g. pacspire.
* addition: like other commands before, 89 DBUS commands and 80 DBUS commands are exported from the library and become directly usable. As far as I'm concerned, this completes the command hardening and direct exportation: the remaining models (82, 85, 92) are ancient, it doesn't make as much sense to export their commands directly.
* bugfix: a crasher in libtifiles, spotted by AddressSanitizer.

The usual links:
* Windows installer download: http://tiplanet.org/beta/setup.exe .
* Source code: https://github.com/debrouxl/tilibs + https://github.com/debrouxl/tilp_and_gfm .
* patches not yet committed to Git: http://tiplanet.org/beta/tilibs_patchset_20130901.tar.bz2, http://tiplanet.org/beta/tilp_and_gfm_patchset_20130901.tar.bz2 (the timestamps are very close to each other because I rewrote nearly every patch to add the forgotten Signed-off-by tag).
* install script for anything non-Windows which is handled by TILP: https://github.com/debrouxl/tilp_and_gfm/blob/master/tilp/trunk/build/scripts/install_tilp.sh .

The TODO list contains items such as, but not limited to:
* finish introduction of a fifth libti* library, dubbed "libtiopers", for factoring code useful to multiple libti* clients. For now, there's pretty little in the new library, and disentangling is not that easy...
* finish GTK+3 compatibility patch;
* add a TILP menu entry for exiting the PTT mode (greyed out if not connected to a Nspire), the feature request indirectly sprang up yesterday again on #omnimaga;
* make Nspire "ROM dumping" (OS dumping) work on all models, by duplicating BrandonW's Fron;
* minor installer and file encoding fixes.

EDIT in 2021: updated the link to the *nix install script.

That's completely outside of my control, AFAICT.

What's the big changes?
Nevermind. Saw the changes.

Oh, and by the way, when sometimes I try to tranfer a file with double click, I get open transmission error. Is that normal?

(HURRAY: 700 posts! :p)

Well, support for either Prizm / fx-CP400, which use Mass Storage Device class, or HP Prime, which uses Mass Storage and Human Interaction Device classes, is best done in completely separate, brand-new code bases. There would hardly be any possibility of sharing code with libti*.
However, sharing some good design bits is both doable and desirable. For instance:
* the layering (charset conversion functions if applicable, file handling functions if applicable, functions for dealing with raw byte transfers on a cable, protocols which are spoken on the wire, and operations which build on protocols) adds a bit of complexity but makes sense;
* structs containing function pointers are a good thing as well (pervasive in e.g. the Linux kernel).