In earlier versions of Maple, the thickness=0 and thickness=1 options both produced the default thickness for lines. In Maple 16, curves are thicker by default. The default thickness is still equivalent to thickness=1, while the thickness=0 option can be used to reproduce the Maple 15 thickness.

Default colors for 2-D plots have changed. See plots:-setcolors for information on how to use different color palettes, including the default palette in earlier versions of Maple. Also, filled plots are now partly transparent.

The default grid used for 3-D surfaces, 2-D implicit plots, 2-D density plots, and contour plots is now [49, 49]. In Maple 15, the number of lines in the wire mesh drawn on top of 3-D surfaces corresponded exactly to the grid, but in Maple 16, a less dense wire mesh is drawn to avoid obscuring surface features.

Your current directory is now automatically appended to the default libname path.  Therefore, libraries and help databases in the current directory are found automatically and can be used implicitly in your current session.

Changing the current working directory will cause an implicit update of libname, making the libraries in the new directory available instead of the ones from the prior path.

For more information, see libname.

When the LinearAlgebra package was introduced in Maple 6, it came with a "programming interface," a subpackage called LA_Main.  As a result of various efficiency improvements to Maple in general over the course of the past several releases, the efficiency benefit of this programming interface has largely disappeared.  Thus, the exports of the LinearAlgebra[LA_Main] module are now the same as the corresponding exports of LinearAlgebra itself.  Code and worksheets which referenced exports of LinearAlgebra[LA_Main] will continue to work, but can now be updated to simply use exports of LinearAlgebra itself with no efficiency loss (and considerable gain in terms of flexibility and ease of use).

When you call ArrayTools[Alias] on an rtable that has an indexing function, ArrayTools[Alias] now returns a readonly alias.  If the option readonly=true is not provided in this case, a warning message is displayed.  For more information, see ArrayTools[Alias].

The changes to Maple's memory manager have deprecated the use of kernelopts(gcfreq).  The decision when to trigger a garbage collection cycle is no longer periodic based upon the number of bytes allocated.  Instead, collection occurs whenever the memory manager identifies that the current memory pool is depleted and needs replenishing.  Accordingly, kernelopts(gcfreq) is now deprecated. For more information, see MemoryManagement.