This page summarizes the changes between tagged releases of Go. For full details, see the Mercurial change log.
++This release includes changes to the io and template packages. +You may need to update your code. + +The io.ReadByter and io.ReadRuner interface types have been renamed to +io.ByteReader and io.RuneReader respectively. + +The order of arguments to template.Execute has been reversed to be consistent +the notion of "destination first", as with io.Copy, fmt.Fprint, and others. + +Gotest now works for package main in directories using Make.cmd-based makefiles. + +The memory allocation runtime problems from the last release are not completely +fixed. The virtual memory exhaustion problems encountered by people using +ulimit -v have been fixed, but there remain known garbage collector problems +when using GOMAXPROCS > 1. + +Other changes: +* 5l: stopped generating 64-bit eor. +* 8l: more work on plan9 support (thanks Yuval Pavel Zholkover). +* archive/zip: handle files with data descriptors. +* arm: working peep-hole optimizer. +* asn1: marshal true as 255, not 1. +* buffer.go: minor optimization, expanded comment. +* build: drop syslog on DISABLE_NET_TESTS=1 (thanks Gustavo Niemeyer), + allow clean.bash to work on fresh checkout, + change "all tests pass" message to be more obvious, + fix spaces in GOROOT (thanks Christopher Nielsen). +* bytes: fix bug in buffer.ReadBytes (thanks Evan Shaw). +* 5g: better int64 code, + don’t use MVN instruction. +* cgo: don't run cgo when not compiling (thanks Gustavo Niemeyer), + fix _cgo_run timestamp file order (thanks Gustavo Niemeyer), + fix handling of signed enumerations (thanks Gustavo Niemeyer), + os/arch dependent #cgo directives (thanks Gustavo Niemeyer), + rename internal f to avoid conflict with possible C global named f. +* codereview: fix hgpatch on windows (thanks Yasuhiro Matsumoto), + record repository, base revision, + use cmd.communicate (thanks Yasuhiro Matsumoto). +* container/ring: replace Iter() with Do(). +* crypto/cipher: add resync open to OCFB mode. +* crypto/openpgp/armor: bug fixes. +* crypto/openpgp/packet: new subpackage. +* crypto/tls: load a chain of certificates from a file, + select best cipher suite, not worst. +* crypto/x509: add support for name constraints. +* debug/pe: ImportedSymbols fixes (thanks Wei Guangjing). +* doc/code: update to reflect that package names need not be unique. +* doc/codelab/wiki: a bunch of fixes (thanks Andrey Mirtchovski). +* doc/install: update for new versions of Mercurial. +* encoding/line: fix line returned after EOF. +* flag: allow hexadecimal (0xFF) and octal (0377) input for integer flags. +* fmt.Scan: scan binary-exponent floating format, 2.4p-3, + hexadecimal (0xFF) and octal (0377) integers. +* fmt: document %%; also %b for floating point. +* gc, ld: detect stale or incompatible object files, + package name main no longer reserved. +* gc: correct receiver in method missing error (thanks Lorenzo Stoakes), + correct rounding of denormal constants (thanks Eoghan Sherry), + select receive bug fix. +* go/printer, gofmt: smarter handling of multi-line raw strings. +* go/printer: line comments must always end in a newline, + remove notion of "Styler", remove HTML mode. +* gob: allow Decode(nil) and have it just discard the next value. +* godoc: use IsAbs to test for absolute paths (fix for win32) (thanks Yasuhiro Matsumoto), + don't hide package lookup error if there's no command with the same name. +* gotest: enable unit tests for main programs. +* http: add Server type supporting timeouts, + add pipelining to ClientConn, ServerConn (thanks Petar Maymounkov), + handle unchunked, un-lengthed HTTP/1.1 responses. +* io: add RuneReader. +* json: correct Marshal documentation. +* netchan: graceful handling of closed connection (thanks Graham Miller). +* os: implement new Process API (thanks Alex Brainman). +* regexp tests: make some benchmarks more meaningful. +* regexp: add support for matching against text read from RuneReader interface. +* rpc: make more tolerant of errors, properly discard values (thanks Roger Peppe). +* runtime: detect failed thread creation on Windows, + faster allocator, garbage collector, + fix virtual memory exhaustion, + implemented windows console ctrl handler (SIGINT) (thanks Hector Chu), + more detailed panic traces, line number work, + improved Windows callback handling (thanks Hector Chu). +* spec: adjust notion of Assignability, + allow import of packages named main, + clarification re: method sets of newly declared pointer types, + fix a few typos (thanks Anthony Martin), + fix Typeof() return type (thanks Gustavo Niemeyer), + move to Unicode 6.0. +* sync: diagnose Unlock of unlocked Mutex, + new Waitgroup type (thanks Gustavo Niemeyer). +* syscall: add SetsockoptIpMreq (thanks Dave Cheney), + add sockaddr_dl, sysctl with routing message support for darwin, freebsd (thanks Mikio Hara), + do not use NULL for zero-length read, write, + implement windows version of Fsync (thanks Alex Brainman), + make ForkExec acquire the ForkLock under windows (thanks Hector Chu), + make windows API return errno instead of bool (thanks Alex Brainman), + remove obsolete socket IO control (thanks Mikio Hara). +* template: add simple formatter chaining (thanks Kyle Consalus), + allow a leading '*' to indirect through a pointer. +* testing: include elapsed time in test output +* windows: replace remaining __MINGW32__ instances with _WIN32 (thanks Joe Poirier). ++