FVSS is essentially an alternative to Utau. It is a frontend (main UI of Utau) and a new wavtool (called wavMOD). It still uses standard Utau resamplers, but will be distributed with a World-based resampler (as they are open source), removing the dependency on Utau completely. At the moment it only supports CV and some CVVC banks, and only those with Romaji encoding (as shift-JIS does **NOT** work with FVSS, it's the Utau locale issue but backwards). It supports fresamp, TIPS, and w4u. Others may work, but Utau's default resampler does NOT. Currently, there is no ability to blend notes (crossfading) or to control pitch besides what key each note will land on. Notes also cannot be moved left and right just yet (but can be moved up and down and resized). There also isn't any way to open projects, or import a .ust or MIDI. You can however save projects, and I recommend you do that anyway because you might be able to open them in the future. So go ahead, give it a try! You can download the latest version at http://fluidvocalsynth.weebly.com Spoiler: original post This is a project I've been working on lately. Essentially what it will be is a replacement for two things: the main UI of Utau (the frontend, main project), and wavtool.exe (using a custom replacement for future features). It is written in C# and will be distributed under an open-source licence (likely MIT or BSD license). As of now, the project has no GUI, just a command line interface as the guts are developed: Right now it cannot use any resampler other than the Utau default one. Also, the custom wav splicer is not finished, so render results are very choppy due to lack of volume envelopes. If you would like to help, what I need right now is a WPF piano roll to use for the GUI, as the lack of one is the reason I'm still using the command-line interface. Another thing that needs a lot of help is the wav splicer. As I mentioned earlier, it cannot add envelopes to the renders, nor can it overlap files. Binary download link will be posted soon, and I'll have the source code up on GitHub some time. EDIT: If you are looking for binary builds, please download the build on my latest posts here and NOT the one on the 5/25 post!