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+# News
+
+## 2.3.1
+
+This is a production release. It fixes a bug that caused `-1000000000 < -1` to
+return `0`. This only happened with negative numbers and only if the value on
+the left was more negative by a certain amount.
+
+## 2.3.0
+
+This is a production release with changes to the build system.
+
+## 2.2.0
+
+This release is a production release. It only has new features and performance
+improvements.
+
+1.	The performance of `sqrt(x)` was improved.
+2.	The new function `root(x, n)` was added to the extended math library to
+	calculate `n`th roots.
+3.	The new function `cbrt(x)` was added to the extended math library to
+	calculate cube roots.
+
+## 2.1.3
+
+This is a non-critical release; it just changes the build system, and in
+non-breaking ways:
+
+1.	Linked locale files were changed to link to their sources with a relative
+	link.
+2.	A bug in `configure.sh` that caused long option parsing to fail under `bash`
+	was fixed.
+
+## 2.1.2
+
+This release is not a critical release.
+
+1.	A few codes were added to history.
+2.	Multiplication was optimized a bit more.
+3.	Addition and subtraction were both optimized a bit more.
+
+## 2.1.1
+
+This release contains a fix for the test suite made for Linux from Scratch: now
+the test suite prints `pass` when a test is passed.
+
+Other than that, there is no change in this release, so distros and other users
+do not need to upgrade.
+
+## 2.1.0
+
+This release is a production release.
+
+The following bugs were fixed:
+
+1.	A `dc` bug that caused stack mishandling was fixed.
+2.	A warning on OpenBSD was fixed.
+3.	Bugs in `ctrl+arrow` operations in history were fixed.
+4.	The ability to paste multiple lines in history was added.
+5.	A `bc` bug, mishandling of array arguments to functions, was fixed.
+6.	A crash caused by freeing the wrong pointer was fixed.
+7.	A `dc` bug where strings, in a rare case, were mishandled in parsing was
+	fixed.
+
+In addition, the following changes were made:
+
+1.	Division was slightly optimized.
+2.	An option was added to the build to disable printing of prompts.
+3.	The special case of empty arguments is now handled. This is to prevent
+	errors in scripts that end up passing empty arguments.
+4.	A harmless bug was fixed. This bug was that, with the pop instructions
+	(mostly) removed (see below), `bc` would leave extra values on its stack for
+	`void` functions and in a few other cases. These extra items would not
+	affect anything put on the stack and would not cause any sort of crash or
+	even buggy behavior, but they would cause `bc` to take more memory than it
+	needed.
+
+On top of the above changes, the following optimizations were added:
+
+1.	The need for pop instructions in `bc` was removed.
+2.	Extra tests on every iteration of the interpreter loop were removed.
+3.	Updating function and code pointers on every iteration of the interpreter
+	loop was changed to only updating them when necessary.
+4.	Extra assignments to pointers were removed.
+
+Altogether, these changes sped up the interpreter by around 2x.
+
+***NOTE***: This is the last release with new features because this `bc` is now
+considered complete. From now on, only bug fixes and new translations will be
+added to this `bc`.
+
+## 2.0.3
+
+This is a production, bug-fix release.
+
+Two bugs were fixed in this release:
+
+1.	A rare and subtle signal handling bug was fixed.
+2.	A misbehavior on `0` to a negative power was fixed.
+
+The last bug bears some mentioning.
+
+When I originally wrote power, I did not thoroughly check its error cases;
+instead, I had it check if the first number was `0` and then if so, just return
+`0`. However, `0` to a negative power means that `1` will be divided by `0`,
+which is an error.
+
+I caught this, but only after I stopped being cocky. You see, sometime later, I
+had noticed that GNU `bc` returned an error, correctly, but I thought it was
+wrong simply because that's not what my `bc` did. I saw it again later and had a
+double take. I checked for real, finally, and found out that my `bc` was wrong
+all along.
+
+That was bad on me. But the bug was easy to fix, so it is fixed now.
+
+There are two other things in this release:
+
+1.	Subtraction was optimized by [Stefan Eßer][14].
+2.	Division was also optimized, also by Stefan Eßer.
+
+## 2.0.2
+
+This release contains a fix for a possible overflow in the signal handling. I
+would be surprised if any users ran into it because it would only happen after 2
+billion (`2^31-1`) `SIGINT`'s, but I saw it and had to fix it.
+
+## 2.0.1
+
+This release contains very few things that will apply to any users.
+
+1.	A slight bug in `dc`'s interactive mode was fixed.
+2.	A bug in the test suite that was only triggered on NetBSD was fixed.
+3.	**The `-P`/`--no-prompt` option** was added for users that do not want a
+	prompt.
+4.	A `make check` target was added as an alias for `make test`.
+5.	`dc` got its own read prompt: `?> `.
+
+## 2.0.0
+
+This release is a production release.
+
+This release is also a little different from previous releases. From here on
+out, I do not plan on adding any more features to this `bc`; I believe that it
+is complete. However, there may be bug fix releases in the future, if I or any
+others manage to find bugs.
+
+This release has only a few new features:
+
+1.	`atan2(y, x)` was added to the extended math library as both `a2(y, x)` and
+	`atan2(y, x)`.
+2.	Locales were fixed.
+3.	A **POSIX shell-compatible script was added as an alternative to compiling
+	`gen/strgen.c`** on a host machine. More details about making the choice
+	between the two can be found by running `./configure.sh --help` or reading
+	the [build manual][13].
+4.	Multiplication was optimized by using **diagonal multiplication**, rather
+	than straight brute force.
+5.	The `locale_install.sh` script was fixed.
+6.	`dc` was given the ability to **use the environment variable
+	`DC_ENV_ARGS`**.
+7.	`dc` was also given the ability to **use the `-i` or `--interactive`**
+	options.
+8.	Printing the prompt was fixed so that it did not print when it shouldn't.
+9.	Signal handling was fixed.
+10.	**Handling of `SIGTERM` and `SIGQUIT`** was fixed.
+11.	The **built-in functions `maxibase()`, `maxobase()`, and `maxscale()`** (the
+	commands `T`, `U`, `V` in `dc`, respectively) were added to allow scripts to
+	query for the max allowable values of those globals.
+12.	Some incompatibilities with POSIX were fixed.
+
+In addition, this release is `2.0.0` for a big reason: the internal format for
+numbers changed. They used to be a `char` array. Now, they are an array of
+larger integers, packing more decimal digits into each integer. This has
+delivered ***HUGE*** performance improvements, especially for multiplication,
+division, and power.
+
+This `bc` should now be the fastest `bc` available, but I may be wrong.
+
+## 1.2.8
+
+This release contains a fix for a harmless bug (it is harmless in that it still
+works, but it just copies extra data) in the [`locale_install.sh`][12] script.
+
+## 1.2.7
+
+This version contains fixes for the build on Arch Linux.
+
+## 1.2.6
+
+This release removes the use of `local` in shell scripts because it's not POSIX
+shell-compatible, and also updates a man page that should have been updated a
+long time ago but was missed.
+
+## 1.2.5
+
+This release contains some missing locale `*.msg` files.
+
+## 1.2.4
+
+This release contains a few bug fixes and new French translations.
+
+## 1.2.3
+
+This release contains a fix for a bug: use of uninitialized data. Such data was
+only used when outputting an error message, but I am striving for perfection. As
+Michelangelo said, "Trifles make perfection, and perfection is no trifle."
+
+## 1.2.2
+
+This release contains fixes for OpenBSD.
+
+## 1.2.1
+
+This release contains bug fixes for some rare bugs.
+
+## 1.2.0
+
+This is a production release.
+
+There have been several changes since `1.1.0`:
+
+1.	The build system had some changes.
+2.	Locale support has been added. (Patches welcome for translations.)
+3.	**The ability to turn `ibase`, `obase`, and `scale` into stacks** was added
+	with the `-g` command-line option. (See the [`bc` manual][9] for more
+	details.)
+4.	Support for compiling on Mac OSX out of the box was added.
+5.	The extended math library got `t(x)`, `ceil(x)`, and some aliases.
+6.	The extended math library also got `r2d(x)` (for converting from radians to
+	degrees) and `d2r(x)` (for converting from degrees to radians). This is to
+	allow using degrees with the standard library.
+7.	Both calculators now accept numbers in **scientific notation**. See the
+	[`bc` manual][9] and the [`dc` manual][10] for details.
+8.	Both calculators can **output in either scientific or engineering
+	notation**. See the [`bc` manual][9] and the [`dc` manual][10] for details.
+9.	Some inefficiencies were removed.
+10.	Some bugs were fixed.
+11.	Some bugs in the extended library were fixed.
+12.	Some defects from [Coverity Scan][11] were fixed.
+
+## 1.1.4
+
+This release contains a fix to the build system that allows it to build on older
+versions of `glibc`.
+
+## 1.1.3
+
+This release contains a fix for a bug in the test suite where `bc` tests and
+`dc` tests could not be run in parallel.
+
+## 1.1.2
+
+This release has a fix for a history bug; the down arrow did not work.
+
+## 1.1.1
+
+This release fixes a bug in the `1.1.0` build system. The source is exactly the
+same.
+
+The bug that was fixed was a failure to install if no `EXECSUFFIX` was used.
+
+## 1.1.0
+
+This is a production release. However, many new features were added since `1.0`.
+
+1.	**The build system has been changed** to use a custom, POSIX
+	shell-compatible configure script ([`configure.sh`][6]) to generate a POSIX
+	make-compatible `Makefile`, which means that `bc` and `dc` now build out of
+	the box on any POSIX-compatible system.
+2.	Out-of-memory and output errors now cause the `bc` to report the error,
+	clean up, and die, rather than just reporting and trying to continue.
+3.	**Strings and constants are now garbage collected** when possible.
+4.	Signal handling and checking has been made more simple and more thorough.
+5.	`BcGlobals` was refactored into `BcVm` and `BcVm` was made global. Some
+	procedure names were changed to reflect its difference to everything else.
+6.	Addition got a speed improvement.
+7.	Some common code for addition and multiplication was refactored into its own
+	procedure.
+8.	A bug was removed where `dc` could have been selected, but the internal
+	`#define` that returned `true` for a query about `dc` would not have
+	returned `true`.
+9.	Useless calls to `bc_num_zero()` were removed.
+10.	**History support was added.** The history support is based off of a
+	[UTF-8 aware fork][7] of [`linenoise`][8], which has been customized with
+	`bc`'s own data structures and signal handling.
+11.	Generating C source from the math library now removes tabs from the library,
+	shrinking the size of the executable.
+12.	The math library was shrunk.
+13.	Error handling and reporting was improved.
+14.	Reallocations were reduced by giving access to the request size for each
+	operation.
+15.	**`abs()` (`b` command for `dc`) was added as a builtin.**
+16.	Both calculators were tested on FreeBSD.
+17.	Many obscure parse bugs were fixed.
+18.	Markdown and man page manuals were added, and the man pages are installed by
+	`make install`.
+19.	Executable size was reduced, though the added features probably made the
+	executable end up bigger.
+20.	**GNU-style array references were added as a supported feature.**
+21.	Allocations were reduced.
+22.	**New operators were added**: `$` (`$` for `dc`), `@` (`@` for `dc`), `@=`,
+	`<<` (`H` for `dc`), `<<=`, `>>` (`h` for `dc`), and `>>=`. See the
+	[`bc` manual][9] and the [`dc` manual][10] for more details.
+23.	**An extended math library was added.** This library contains code that
+	makes it so I can replace my desktop calculator with this `bc`. See the
+	[`bc` manual][3] for more details.
+24.	Support for all capital letters as numbers was added.
+25.	**Support for GNU-style void functions was added.**
+26.	A bug fix for improper handling of function parameters was added.
+27.	Precedence for the or (`||`) operator was changed to match GNU `bc`.
+28.	`dc` was given an explicit negation command.
+29.	`dc` was changed to be able to handle strings in arrays.
+
+## 1.1 Release Candidate 3
+
+This release is the eighth release candidate for 1.1, though it is the third
+release candidate meant as a general release candidate. The new code has not
+been tested as thoroughly as it should for release.
+
+## 1.1 Release Candidate 2
+
+This release is the seventh release candidate for 1.1, though it is the second
+release candidate meant as a general release candidate. The new code has not
+been tested as thoroughly as it should for release.
+
+## 1.1 FreeBSD Beta 5
+
+This release is the sixth release candidate for 1.1, though it is the fifth
+release candidate meant specifically to test if `bc` works on FreeBSD. The new
+code has not been tested as thoroughly as it should for release.
+
+## 1.1 FreeBSD Beta 4
+
+This release is the fifth release candidate for 1.1, though it is the fourth
+release candidate meant specifically to test if `bc` works on FreeBSD. The new
+code has not been tested as thoroughly as it should for release.
+
+## 1.1 FreeBSD Beta 3
+
+This release is the fourth release candidate for 1.1, though it is the third
+release candidate meant specifically to test if `bc` works on FreeBSD. The new
+code has not been tested as thoroughly as it should for release.
+
+## 1.1 FreeBSD Beta 2
+
+This release is the third release candidate for 1.1, though it is the second
+release candidate meant specifically to test if `bc` works on FreeBSD. The new
+code has not been tested as thoroughly as it should for release.
+
+## 1.1 FreeBSD Beta 1
+
+This release is the second release candidate for 1.1, though it is meant
+specifically to test if `bc` works on FreeBSD. The new code has not been tested as
+thoroughly as it should for release.
+
+## 1.1 Release Candidate 1
+
+This is the first release candidate for 1.1. The new code has not been tested as
+thoroughly as it should for release.
+
+## 1.0
+
+This is the first non-beta release. `bc` is ready for production use.
+
+As such, a lot has changed since 0.5.
+
+1.	`dc` has been added. It has been tested even more thoroughly than `bc` was
+	for `0.5`. It does not have the `!` command, and for security reasons, it
+	never will, so it is complete.
+2.	`bc` has been more thoroughly tested. An entire section of the test suite
+	(for both programs) has been added to test for errors.
+3.	A prompt (`>>> `) has been added for interactive mode, making it easier to
+	see inputs and outputs.
+4.	Interrupt handling has been improved, including elimination of race
+	conditions (as much as possible).
+5.	MinGW and [Windows Subsystem for Linux][1] support has been added (see
+	[xstatic][2] for binaries).
+6.	Memory leaks and errors have been eliminated (as far as ASan and Valgrind
+	can tell).
+7.	Crashes have been eliminated (as far as [afl][3] can tell).
+8.	Karatsuba multiplication was added (and thoroughly) tested, speeding up
+	multiplication and power by orders of magnitude.
+9.	Performance was further enhanced by using a "divmod" function to reduce
+	redundant divisions and by removing superfluous `memset()` calls.
+10.	To switch between Karatsuba and `O(n^2)` multiplication, the config variable
+	`BC_NUM_KARATSUBA_LEN` was added. It is set to a sane default, but the
+	optimal number can be found with [`karatsuba.py`][4] (requires Python 3)
+	and then configured through `make`.
+11.	The random math test generator script was changed to Python 3 and improved.
+	`bc` and `dc` have together been run through 30+ million random tests.
+12.	All known math bugs have been fixed, including out of control memory
+	allocations in `sine` and `cosine` (that was actually a parse bug), certain
+	cases of infinite loop on square root, and slight inaccuracies (as much as
+	possible; see the [README][5]) in transcendental functions.
+13.	Parsing has been fixed as much as possible.
+14.	Test coverage was improved to 94.8%. The only paths not covered are ones
+	that happen when `malloc()` or `realloc()` fails.
+15.	An extension to get the length of an array was added.
+16.	The boolean not (`!`) had its precedence change to match negation.
+17.	Data input was hardened.
+18.	`bc` was made fully compliant with POSIX when the `-s` flag is used or
+	`POSIXLY_CORRECT` is defined.
+19.	Error handling was improved.
+20.	`bc` now checks that files it is given are not directories.
+
+## 1.0 Release Candidate 7
+
+This is the seventh release candidate for 1.0. It fixes a few bugs in 1.0
+Release Candidate 6.
+
+## 1.0 Release Candidate 6
+
+This is the sixth release candidate for 1.0. It fixes a few bugs in 1.0 Release
+Candidate 5.
+
+## 1.0 Release Candidate 5
+
+This is the fifth release candidate for 1.0. It fixes a few bugs in 1.0 Release
+Candidate 4.
+
+## 1.0 Release Candidate 4
+
+This is the fourth release candidate for 1.0. It fixes a few bugs in 1.0 Release
+Candidate 3.
+
+## 1.0 Release Candidate 3
+
+This is the third release candidate for 1.0. It fixes a few bugs in 1.0 Release
+Candidate 2.
+
+## 1.0 Release Candidate 2
+
+This is the second release candidate for 1.0. It fixes a few bugs in 1.0 Release
+Candidate 1.
+
+## 1.0 Release Candidate 1
+
+This is the first Release Candidate for 1.0. `bc` is complete, with `dc`, but it
+is not tested.
+
+## 0.5
+
+This beta release completes more features, but it is still not complete nor
+tested as thoroughly as necessary.
+
+## 0.4.1
+
+This beta release fixes a few bugs in 0.4.
+
+## 0.4
+
+This is a beta release. It does not have the complete set of features, and it is
+not thoroughly tested.
+
+[1]: https://docs.microsoft.com/en-us/windows/wsl/install-win10
+[2]: http://xstatic.musl.cc/bc/
+[3]: http://lcamtuf.coredump.cx/afl/
+[4]: ./karatsuba.py
+[5]: ./README.md
+[6]: ./configure.sh
+[7]: https://github.com/rain-1/linenoise-mob
+[8]: https://github.com/antirez/linenoise
+[9]: ./manuals/bc.1.ronn
+[10]: ./manuals/dc.1.ronn
+[11]: https://scan.coverity.com/projects/gavinhoward-bc
+[12]: ./locale_install.sh
+[13]: ./manuals/build.md
+[14]: https://github.com/stesser