CGAL 2.2 differs from CGAL 2.1 in the platforms that are supported and in functionality:

## Changelog

### Supported platforms

- The KAI compiler (4.0) on Solaris 5.8
- Borland C++ (5.5)

### General

- There is a new, non-reference-counted kernel,
`Simple_cartesian`

. Because reference counting is not used, and thus coordinates are stored within a class, debugging is easier using this kernel. This kernel can also be faster in some cases than the reference-counted`Cartesian kernel`

. - A generator for ``random’’ simple polygons is now available.
- In directory demo/Robustness, programs that demonstrate typical robustness problems in geometric computing are presented along with the solutions to these problems that CGAL provides.
- The binary operations on polygons (union, intersection …) have been removed. Those operations were not documented in the previous release (2.1). Arrangements can often be used as a substitute.

### New optimisation algorithms

`Min_annulus_d`

: Algorithm for computing the smallest enclosing annulus of points in arbitrary dimension`Polytope_distance_d`

: Algorithm for computing the (squared) distance between two convex polytopes in arbitrary dimension`Width_3`

: Algorithm for computing the (squared) width of points sets in three dimensions

### 2D Triangulations

- There are now two triangulation data structures available in CGAL. The new one uses a list to store the faces and allows one to represent two-dimensional triangulations embedded in three spaces as well as planar triangulations.
- The triangulation hierarchy which allows fast location query is now available.

### 3D Triangulations

- Removal as well as insertions of vertices for 3D Delaunay triangulations is now possible.

### Planar Maps

- Inifinite objects can now be included in planar maps.