Hi, i'm very interested in software for making animations, unfortunately, sometimes FOSS solutions aren't enough/good, other times commercial solution are good, but not supported for Linux and working them via Wine may prove to be a nightmare, i want to know if some of you know a good program for the making of animations, 2D preferably, saving you some effort to mention some programs, i'll list here the ones i have tested/used:

Pencil

Pros: Works as expected, has a timeline, custom frame rate and it's under constant development
Cons: While easy panning/zoom with wheel mouse is becoming a standard, controls in pencil aren't that conventional, plus, has no tweening, vector layer is quite primitive and sometimes the tracing tools behave buggy on simple task such as brush color or size, even worst, is a nightmare for mouse-only users

Ktoon

Pros: A good program back in version 0.8, stood strong against other programs and was always a good option, it had the basics, drawing tools and timeline/exposure sheet, export options and things
Cons: It's fate is unknown now, it might get commercial or something, and the current version is unstable.

Tupi

Pros: New and fresh fork of Ktoon, it has now Motion tween and the option for use SVG graphics, and minor improvements which are nice to see
Cons: Very unstable, the basic tools for drawing and handling objects are inaccurate, is still beta.

Synfig Studio

Pros: Excellent quality, many ways to export an animation, nice effects and an interesting way to tweening.
Cons: Most users complain of it's complexity, not my case as the Documentation is for that purpose, what is giving me headaches now is that is now unusable as the speed drops near to program freezing, no one knows/care/want to hear about the cause

Anime Studio

Pros: Very interesting tool, it was and still is good since the time it was called Moho, now it even has effects simulation
Cons: Versions 5 and 6 were good, while version 7 is available for Mac and Win, there is no version for Linux last time i checked, also.. there is thigs little thing that annoy me about Win and Mac being better/more supported than the Linux one...
Under Wine: I purchased version 7 for windows to use through Wine, is impressive and things but Wine itself can't take some native work for windows, making rendering the project crash the program, also with the use of the program the speed of the program itself starts to drop

Flash 8 (Wine)

Pros: I fell in love back in 2004 when for first time i used Macormedia Flash, and used it untill i changed to Linux, using it through Wine make it work decently well.
Cons: Many little glitches in the user interface, Adobe versions don't install, and using flash in long projects make it slow.

GIMP

Pros: I have made little animation inside Gimp, each layer counts as frame, Gimp is an excelente piece for effects and creation of graphics itself, if someone build a timeline (Independent from the layers) for gimp let me know, that would make it perfect
Cons: The more layers as frames you use, the more memory it takes, natively, GAP might help on exporting the animation and natively exporting to GIF is the only way to render an animation, also Gimp doesn't export layers as png, there is a plugin for that tho..

Creatoon (Wine)

Pros: Interesting Cutout animation program, went free for some unknown reason, it has an excelent control over objects.
Cons: Some releases of Wine make it crash, some make it works flawlesly, and some updates leave it buggy... the program itself works well, but some changes in Wine itself may cause some problems.

Styckz (Wine)

Pros: A newest program for make stick animations, it has some fun options
Cons: No further complains than it takes huge amounts of memory via Wine, and the eternal promise of a Linux version is still showing on their download page.

StickyPy

Pros: Can natively run in Linux as it is written in Python
Cons: Usable and stable, but still...

mtPaint

Pros: Pixel art program (Hurray!!) which contains some nice features for the making of gifs
Cons: Pretty much the same with GIMP, indeed, is better exporting gifs from GIMP.

Notes:

I didn't tested ToonBoom! and TvPaint, i know about their existence, but seems that these need higher requirements that the ones i have, also i'm not counting 3D editors because only Blender and K-3D are worth of use under Linux, there are some outdated programs that don't run anymore in new distros, or that are abandoned, unstable, no longer maintained or unexplainable unusable, here i list some minor programs that caught my attention but for different reason aren't good options:

Java Animation Studio
Animata
F4L
ganim8
Gnash

well.. hopping there are some new answer soon, greetings!