All the samples I saw can easily be accomplished with Bezier curves.
Other drawing programs have other spline tools in addition to the ubiquitous Bezier tool.
FreeHand's Bezigon tool draws Beziers, but does so with an interface that lets you just click where you want points on the path, and then auto-conforms the curve points that you place according to where you place the next point, yielding results much like the Java applet you linked to.
Canvas's Auto Curve tool behaves almost exactly like the Java applet.
Although I'm not opposed to a drawing program having multiple interfaces for creating spline curves, I have no desire for them. I never use the Bezigon tool in FH, and never use the Auto Curve tool in Canvas. I view them both as accommodations to beginners who initially think Bezier tools are unapproachable. I dare say the vast majority of proficient vector illustrators would agree. (No offense intended to any experienced users who find them useful.)
So while I can't say whether Canvas's Auto Curve tool actually uses the Akima equation you seem to be fond of, it's interface and behavior seems identical to what you seem to desire, and in that respect is therefore nothing new to drawing programs.
As far as Illustrator goes, I'd much rather development time be dedicated to far more fundamental and universally important things that it still lacks relative to the other mainstream drawing programs.
Illustrator still has no decent cutting tool. No user-defined drawing scales. No dimension tools. No connector tools. Poor snap behavior. Too limited value entry fields. Excruciating text performance. Bizarre Character and Paragraph style behaviors. No geometric shape primitives. No proper radius/chamfer/fillet feature. No joining of multiple paths at once. An old-fashioned modal-dialog-heavy and poorly-organized and too-cluttered interface. The list is quite long; and on my list (for whatever it's worth), alternate interfaces for interactively drawing spline curves point-by-point does not even appear.
The Bezier curve is inherent to PostScript drawing programs, and the conventional click-or-clickdrag interface for them is practically universal. It is fluid, accurate, supple, and economical in the number of points it creates. It dominates for good reason. (That's not to say AI's particular implementation of it couldn't be better; it could. FreeHand's is better.)
So while I'm all for truly valuable "new wrinkles," this is one I don't see any practical need for.
What actual benefit do you see in it?
I have been asking for this *^$%# feature forever.
I've been using Adobe Illustrator for over a year and I still cannot draw the same things which I can draw easily when I use Microsoft Expression Design and the B-Spline.
However I use a Mac, and I don't want to boot parallels every time I need to draw something.
For example... Try to draw a pear using the Adobe method versus the Microsoft method. It's *&$#%* impossible.
You would think a thousands of dollars program would include every *&%^*#$ possible spline tool known to man. Yet they include the most obtuse and impossible way of drawing curves. It's like the central core of what a vector graphics program aught to do, however they don't even support the form of curve supported in FREE software.
Then when you ask for it, they say that their tool is more powerful. Give me a *&#%& break. I have been trying to use it for over a year. You don't know what powerful is if you can't do *&#%& with it.
Adobe Illustrator was specifically designed to produce PostScript(TM) output from its very first version; and PostScript exclusively uses Bezier curves.
In addition, Adobe Illustrator v1.0 preceded Windows NT by about 7 years.
great. I was wrong. add the feature. thanks in advance.