Klayout

* RBA bugfix: RdbItem.each_value was not working on const references.
* DXF reader and writer enhancements for improved interoperability with
other tools.
* Unit option for DXF input (to specify the units of the drawing).
* Bugfix: layer mapping was not working correctly for DXF and CIF output.

* Added cell margins for fill utility.
* A couple of bugs fixed (related to Diff tool, marker database reader,
Ruby scripting).
* Source is compatible with earlier versions of Qt now (down to 4.2.3).
* Bugfix: persistency of reader options was broken.
* Enhanced DXF and CIF reader and writer functionality with improved
compatibility with other systems.

* Support for DXF format (reading and writing).
ASCII and binary format are supported. There is an open issue how to
represent layouts with multiple top cells. Currently, the ENTITY section
is always empty and all cells are put into BLOCKS sections. DXF units
will be micron and the database unit must be selected manually when
layouts are read.
* Support for CIF format (reading and writing).
There is an open issue how to deal with paths. By default, CIF states
that paths are supposed to have round ends. Obviously that interpretation
is not commonly used. Options are provided which control how path objects
are read and written.
* Tabs for the layer panel. This feature is explained here.
* Flat cell list and cell list sorting modes. The feature is explained here.
* Dockable tool boxes.
Layer list, cell list, layer toolbox and navigator are now dockable and
can be dragged to another location, torn off the main window or closed
with Qt's standard dockable window controls. The position and the state
of the dockable windows is saved in the settings and session files.
* A ruler embedded in the background image.
Now, a small ruler is embedded into the background which shows the
dimension scale similar to a map. It can be disabled in the setup dialog
on the "Display/Background" page.
* Image quality enhancement by oversampling. The feature is explained here.
* The "Diff" tool. The Diff tool produces a marker database containing a
description of the differences. A detailed description can be found here.
* Snapping to objects is provided as an option for edit mode. In this mode,
the mouse snaps to vertices and edges of visible objects. This mode can
be enabled with the "Objects" checkbox on the "Editor Options" page (F3
key or "Edit/Editor Options" menu).
* The reference point for the placement of instances now is the lower left
point of the placed cell's bounding box, not the origin.
* Dialog geometry persistent now.
Marker, shape and instance browsers now save their geometries and
splitter pane configurations when the application exits.
* Instance placement now uses bbox origin, not cell origin.
This simplifies placement of cells with their origin not aligned with
the content.
* Fill (tiling) tool. The tool is found in "Edit/Utilities/Fill Tool". A
detailed description can be found here.
* In some places, particular in the ruler display string, expressions can
be used. For rulers, the previous display string placeholder scheme is
replaced by the more powerful expression expansion scheme (see Ruler
properties for details).
* Build support for VC++ and Visual Studio 2010. The Windows 64bit build
now is based on that environment. Note: Visual Studio 2010 no longer
supports Windows 2000. To use KLayout on Windows 2000, a legacy build
based on MinGW is provided.

* Bugfix: marker browser crashed when opened from menu and the maximum
number of markers was set differently from default.

* Navigator now allows to drag a zoom box in the usual way.
* Paths with odd width (in database units) are shown correctly.
* Some bugfixes (for a list of fixed bugs see Known bugs in version 0.20)
concerning the net tracer and the Gerber import feature.
* Support for Ruby 1.9 (experimental).
* Support for 64 bit Windows (experimental).

* Import option for Gerber PCB data ("File/Import" menu entry). Details
about this function can be found in the Importing Gerber PCB files
section in the advanced features manual.
* A function to import another stream file into the current file.
This avoids having to use copy & paste and provides a couple of nice
options. Details about this function can be found in the Importing other
layout files section in the advanced features manual.
* A simple XOR tool providing a flat XOR between two layouts. A tolerance
can be set to suppress small deviations. A tiling option is provided to
reduce memory requirements for large layouts. The flat approach probably
limits the application to "almost flat", small to medium sized layouts.
Details about this function can be found in the The XOR tool section in
the advanced features manual.
* A net tracing tool to trace single nets of conductive layers connected
through via shapes. The function is intended for extracting single small
nets and it's not performance optimized for the case of huge power nets.
Details about this function can be found in the The net tracing feature
section in the advanced features manual.
* A navigator window that shows current view's rectangle and allows to
control the rectangle by dragging or resizing it.
* Multi threading support for drawing increases the drawing performance on
multi-core CPU's by rendering different layers on different CPU's. The
number of threads to use can be set in the setup dialog in the "Display"
group under "Optimizations". By default, a single thread is used.
* "Make array" method ("Edit/Selection" menu) to multiply the selection
into an array arrangement.
* A function to add a layout already loaded to a view ("File/Pull In
Other Layout").
* A function to scan a layer's geometry and create a marker database from
that. The menu function is found in the "Tools/Verification" menu. It
will scan all selected layers either flat or hierarchical and create a
marker database containing the shapes as markers.
* Layer mapping on input: the reader options now allow to specify a
mapping together with a layer specification. In addition to specifying
the layers to read, a target can be given which specifies which layer
the shapes will be stored under (See "Reader Options" dialog found in
the "File" menu).
* A couple of new display options:
o Abstract mode (shows only the outer interfacing shapes of child cells.
o Child hierarchy level layout can be configured to be shown in different
brightness, hollow fill or static neutral color to differentiate top
level from bottom level layout.
o Enhancements for the hierarchy level specifications in the layer source
notation.
* A log viewer is provided to catch warning messages. The menu entry to open
the log viewer is found in the "File" menu.
* The setup dialog has been reorganized to make room for more property pages.
* Instances now show the cell's content when being moved instead just a
rectangle. This feature can be disabled.
* Various usability enhancements (i.e. mouse cursor now shows activity,
status bar shows short shape statistics etc.).
* An option to not write empty cells.
* Support for missing cells in the input layout: those cells get marked and
are not produced in the output unless they have received content. That
allows to load and save layouts with missing cells without producing empty
cells for those missing cells.
* Some new functions in the layer list context menu ("Show All", "Hide All",
"Show Only Selected").
* Various bug fixes (i.e. for clip function).
* A couple of new RBA methods.