- Support splat expansions inside tuple and array literals. ([#10429](https://github.com/crystal-lang/crystal/pull/10429), thanks @HertzDevil)
- Support breaks with values inside `while` expressions. ([#10566](https://github.com/crystal-lang/crystal/pull/10566), thanks @HertzDevil)
- Add `@top_level` to access the top-level scope in macros. ([#10682](https://github.com/crystal-lang/crystal/pull/10682), thanks @beta-ziliani)
- Fix: preserve integer sizes in `NumberLiteral#int_bin_op`. ([#10713](https://github.com/crystal-lang/crystal/pull/10713), thanks @collidedscope)
- Add `NumberLiteral#to_number`. ([#10802](https://github.com/crystal-lang/crystal/pull/10802), thanks @straight-shoota)
- **(breaking-change)** Add `Crystal::Macros::Path#global?` deprecating the old `Crystal::Macros::Path#global`. ([#10812](https://github.com/crystal-lang/crystal/pull/10812), thanks @HertzDevil)
- Minor fixes to docs of `UnaryExpression` macro nodes. ([#10816](https://github.com/crystal-lang/crystal/pull/10816), thanks @HertzDevil)
- Add macro method `ASTNode#nil?`. ([#10850](https://github.com/crystal-lang/crystal/pull/10850), [#10616](https://github.com/crystal-lang/crystal/pull/10616), thanks @straight-shoota)
- Port `Socket::Address` to win32 . ([#10610](https://github.com/crystal-lang/crystal/pull/10610), thanks @straight-shoota)
- Port `Socket::Addrinfo` to win32. ([#10650](https://github.com/crystal-lang/crystal/pull/10650), thanks @straight-shoota)
- Extract system-specifics from Socket. ([#10706](https://github.com/crystal-lang/crystal/pull/10706), thanks @straight-shoota)
- Make `WinError` portable and add it to prelude. ([#10725](https://github.com/crystal-lang/crystal/pull/10725), thanks @straight-shoota)
- Improve portability of `SystemError`. ([#10726](https://github.com/crystal-lang/crystal/pull/10726), thanks @straight-shoota)
- Refactor `Socket::Addrinfo::Error` based on `os_error `. ([#10761](https://github.com/crystal-lang/crystal/pull/10761), thanks @straight-shoota)
- Add `WinError.wsa_value` and specs for `WinError`. ([#10762](https://github.com/crystal-lang/crystal/pull/10762), thanks @straight-shoota)
- Add specs for `Errno`. ([#10763](https://github.com/crystal-lang/crystal/pull/10763), thanks @straight-shoota)
- Refactor: Move win32 libc bindings from `winbase.cr` to approriate files. ([#10771](https://github.com/crystal-lang/crystal/pull/10771), thanks @straight-shoota)
- Refactor: Change protocol socket fd to `Socket::Handle`. ([#10772](https://github.com/crystal-lang/crystal/pull/10772), thanks @straight-shoota)
- Fix `Socket::Connect` error in addrinfo inherit `os_error`. ([#10782](https://github.com/crystal-lang/crystal/pull/10782), thanks @straight-shoota)
- Reorganize some win32 libc bindings ([#10776](https://github.com/crystal-lang/crystal/pull/10776), thanks @straight-shoota)
- Add type restriction to private `Process` constructor. ([#7040](https://github.com/crystal-lang/crystal/pull/7040), thanks @z64)
- Add various return type restrictions (thanks @oprypin, @straight-shoota, and @caspiano):
[#10578](https://github.com/crystal-lang/crystal/pull/10578), [#10579](https://github.com/crystal-lang/crystal/pull/10579),
[#10580](https://github.com/crystal-lang/crystal/pull/10580), [#10581](https://github.com/crystal-lang/crystal/pull/10581),
[#10582](https://github.com/crystal-lang/crystal/pull/10582), [#10583](https://github.com/crystal-lang/crystal/pull/10583),
[#10584](https://github.com/crystal-lang/crystal/pull/10584), [#10585](https://github.com/crystal-lang/crystal/pull/10585),
[#10586](https://github.com/crystal-lang/crystal/pull/10586), [#10587](https://github.com/crystal-lang/crystal/pull/10587),
[#10588](https://github.com/crystal-lang/crystal/pull/10588), [#10849](https://github.com/crystal-lang/crystal/pull/10849),
[#10856](https://github.com/crystal-lang/crystal/pull/10856), [#10857](https://github.com/crystal-lang/crystal/pull/10857),
[#10858](https://github.com/crystal-lang/crystal/pull/10858), [#10905](https://github.com/crystal-lang/crystal/pull/10905)
- Add type restrictions for splat-less overloads of some methods. ([#10594](https://github.com/crystal-lang/crystal/pull/10594), thanks @HertzDevil)
- Add `Number.new` overload for `String`. ([#10422](https://github.com/crystal-lang/crystal/pull/10422), thanks @Blacksmoke16)
- Fix `Math.pw2ceil` for zero and 64-bit integers. ([#10555](https://github.com/crystal-lang/crystal/pull/10555), thanks @straight-shoota)
- Add `#positive?` & `#negative?` to `Number` and `Time::Span`. ([#10601](https://github.com/crystal-lang/crystal/pull/10601), thanks @Blacksmoke16)
- Fix imprecise `Number#significant` algorithm. ([#10615](https://github.com/crystal-lang/crystal/pull/10615), thanks @straight-shoota)
- Add `BigFloat`'s rounding modes. ([#10618](https://github.com/crystal-lang/crystal/pull/10618), thanks @HertzDevil)
- Fix handling of arithmetic overflow in `BigDecimal#div`. ([#10628](https://github.com/crystal-lang/crystal/pull/10628), thanks @kellydanma)
- Clarify behaviour of unsafe `Float`-to-number conversions. ([#10631](https://github.com/crystal-lang/crystal/pull/10631), thanks @HertzDevil)
- Fix return type restriction for `Number#humanize` overload. ([#10633](https://github.com/crystal-lang/crystal/pull/10633), thanks @HertzDevil)
- Fix `printf` float with with many digits. ([#10719](https://github.com/crystal-lang/crystal/pull/10719), thanks @straight-shoota)
- Add `BigDecimal`'s missing rounding modes. ([#10798](https://github.com/crystal-lang/crystal/pull/10798), thanks @HertzDevil)
- Add support for using big rational `#**` with unsigned ints. ([#10887](https://github.com/crystal-lang/crystal/pull/10887), thanks @stakach)
- Add overflow detection to `BigFloat#to_i64` and `#to_u64`. ([#10630](https://github.com/crystal-lang/crystal/pull/10630), thanks @HertzDevil)
- **(performance)** Optimize `Levenshtein.distance`. ([#8324](https://github.com/crystal-lang/crystal/pull/8324), thanks @r00ster91)
- Refactor: add private `Slice#hexdump(io : IO)` overload. ([#10496](https://github.com/crystal-lang/crystal/pull/10496), thanks @HertzDevil)
- Restrict `MatchData#begin` and `#end` to `Int32`. ([#10656](https://github.com/crystal-lang/crystal/pull/10656), thanks @straight-shoota)
- Refactor: remove `#check_needs_resize` from `IO::Memory`, `String::Builder`. ([#10732](https://github.com/crystal-lang/crystal/pull/10732), thanks @straight-shoota)
- Fix `Base64#encode`, exclude last 3 bytes from bswap. ([#10752](https://github.com/crystal-lang/crystal/pull/10752), thanks @kostya)
- Refactor: avoid union type in `Char::Reader#decode_char_at`. ([#10758](https://github.com/crystal-lang/crystal/pull/10758), thanks @asterite)
- Add sub/superset checking methods to `Hash`. ([#7500](https://github.com/crystal-lang/crystal/pull/7500), thanks @Sija)
- Improve documentation of `Array#[](Range)`. ([#10243](https://github.com/crystal-lang/crystal/pull/10243), thanks @straight-shoota)
- Add `Steppable` module as generalized `Number#step`. ([#10279](https://github.com/crystal-lang/crystal/pull/10279), thanks @straight-shoota)
- Add docs for `#map_with_index`. ([#10512](https://github.com/crystal-lang/crystal/pull/10512), thanks @wontruefree)
- Add `Array#truncate`. ([#10712](https://github.com/crystal-lang/crystal/pull/10712), thanks @HertzDevil)
- Fix: Always copy `Hash`'s default block on `#dup` and `#clone`. ([#10744](https://github.com/crystal-lang/crystal/pull/10744), thanks @HertzDevil)
- Apply `Array#push`'s resizing heuristic to `#unshift`. ([#10750](https://github.com/crystal-lang/crystal/pull/10750), thanks @HertzDevil)
- Refactor index / count normalization in range-like methods. ([#10753](https://github.com/crystal-lang/crystal/pull/10753), thanks @HertzDevil)
- Add methods for cumulative folding and prefix sums. ([#10789](https://github.com/crystal-lang/crystal/pull/10789), thanks @HertzDevil)
- Fix: Pass read-only flag to peeked slice in `IO::Memory`. ([#10891](https://github.com/crystal-lang/crystal/pull/10891), thanks @z64)
- Add methods for getting peer certificates and signatures in `OpenSSL`. ([#8005](https://github.com/crystal-lang/crystal/pull/8005), thanks @will)
- Add docs for `OpenSSL::Cipher`. ([#9934](https://github.com/crystal-lang/crystal/pull/9934), thanks @sol-vin)
- Fix format of `src/openssl/cipher.cr`. ([#10705](https://github.com/crystal-lang/crystal/pull/10705), thanks @straight-shoota)
- Refine documentation for `Random#urlsafe_base64`. ([#10724](https://github.com/crystal-lang/crystal/pull/10724), thanks @straight-shoota)
- Fix ssl context required for `add_x509_verify_flags`. ([#10756](https://github.com/crystal-lang/crystal/pull/10756), thanks @stakach)
- Improve error handling for `load_localtime` on unix. ([#10654](https://github.com/crystal-lang/crystal/pull/10654), thanks @straight-shoota)
- Fix broken call to `Time#to_s`. ([#10778](https://github.com/crystal-lang/crystal/pull/10778), thanks @straight-shoota)
- Fix `Time#shift` cover date boundaries with zone offset. ([#10871](https://github.com/crystal-lang/crystal/pull/10871), thanks @straight-shoota)
- Fix and unify documentation for `puts`. ([#10614](https://github.com/crystal-lang/crystal/pull/10614), thanks @straight-shoota)
- Fix `Path#sibling` return type. ([#10655](https://github.com/crystal-lang/crystal/pull/10655), thanks @Sija)
- Add `Path` in `FileUtils`'s methods to match the interfaces it's wrapping. ([#10747](https://github.com/crystal-lang/crystal/pull/10747), thanks @yb66)
- Fix `FileDescriptor#pos` return `Int64` on armv6 ([#10845](https://github.com/crystal-lang/crystal/pull/10845), thanks @straight-shoota)
- Clarify documentation on `Path#join` and `#==`. ([#10455](https://github.com/crystal-lang/crystal/pull/10455), thanks @straight-shoota)
- Add an example middleware for `remote_address`. ([#10408](https://github.com/crystal-lang/crystal/pull/10408), thanks @oprypin)
- Add `OAuth2::Client#http_client`. ([#10452](https://github.com/crystal-lang/crystal/pull/10452), thanks @straight-shoota)
- Fix undefined constant error for `http/params`. ([#10537](https://github.com/crystal-lang/crystal/pull/10537), thanks @stakach)
- Fix looping forever at 100% CPU if socket is closed. ([#10658](https://github.com/crystal-lang/crystal/pull/10658), thanks @didactic-drunk)
- Fix documentation of `HTTP::Cookies#[]=` empty path. ([#10669](https://github.com/crystal-lang/crystal/pull/10669), thanks @straight-shoota)
- Fix handling of `EAI_SYSTEM` for `getaddrinfo`. ([#10757](https://github.com/crystal-lang/crystal/pull/10757), thanks @straight-shoota)
- **(performance)** Cache `socket.local_address` and `socket.remote_address`. ([#10765](https://github.com/crystal-lang/crystal/pull/10765), thanks @lbguilherme)
- Fix: `IO::ARGF#read` should always return `i32`. ([#10828](https://github.com/crystal-lang/crystal/pull/10828), thanks @stakach)
- Fix `HTTP::Cookie` parse quoted cookie value. ([#10853](https://github.com/crystal-lang/crystal/pull/10853), thanks @straight-shoota)
- Add `Socket::Addrinfo#inspect` ([#10775](https://github.com/crystal-lang/crystal/pull/10775), thanks @straight-shoota)
- Fix sentence structure in `process.cr`. ([#9259](https://github.com/crystal-lang/crystal/pull/9259), thanks @matthewmcgarvey)
- Implement segfault handler in Crystal. ([#10463](https://github.com/crystal-lang/crystal/pull/10463), thanks @maxfierke)
- Improve documentation for `Pointer.malloc` and `GC` methods. ([#10644](https://github.com/crystal-lang/crystal/pull/10644), thanks @straight-shoota)
- Add links to literal types in the language reference. ([#10827](https://github.com/crystal-lang/crystal/pull/10827), thanks @straight-shoota)
- Add docs for some json methods. ([#10257](https://github.com/crystal-lang/crystal/pull/10257), thanks @rdp)
- Add `UUID.from_json_object_key?`. ([#10517](https://github.com/crystal-lang/crystal/pull/10517), thanks @kalinon)
- Fix `JSON::Lexer`'s UTF-16 escape sequence parsing. ([#10450](https://github.com/crystal-lang/crystal/pull/10450), thanks @HertzDevil)
- Fix `YAML::Serializable.use_yaml_discriminator` with typed enum. ([#10460](https://github.com/crystal-lang/crystal/pull/10460), thanks @straight-shoota)
- Fix YAML to not parse empty string as `nil`. ([#10608](https://github.com/crystal-lang/crystal/pull/10608), thanks @straight-shoota)
- Add `UUID` to yaml parsing. ([#10715](https://github.com/crystal-lang/crystal/pull/10715), thanks @kalinon)
- Fix double flushing json/yaml builders. ([#10716](https://github.com/crystal-lang/crystal/pull/10716), thanks @matthewmcgarvey)
- Add spec helper `it_iterates` for iteration methods. ([#10158](https://github.com/crystal-lang/crystal/pull/10158), [#10797](https://github.com/crystal-lang/crystal/pull/10797), thanks @straight-shoota)
- Add usage instructions for spec runner to compiler. ([#10046](https://github.com/crystal-lang/crystal/pull/10046), thanks @straight-shoota)
- Fix: Handle invalid option errors on `crystal spec`. ([#10787](https://github.com/crystal-lang/crystal/pull/10787), thanks @hugopl)
- Include `spec/**` in docs_main. ([#10863](https://github.com/crystal-lang/crystal/pull/10863), thanks @straight-shoota)
- Add support for type var splats inside `Tuple` during generic parameter substitution. ([#10232](https://github.com/crystal-lang/crystal/pull/10232), thanks @HertzDevil)
- Fix: consider free vars in parameters of abstract def implementations before existing types, in particular fixing the creation of empty types. ([#10503](https://github.com/crystal-lang/crystal/pull/10503), thanks @HertzDevil)
- Fix variance checks between generic instances for `Proc#call` and abstract defs. ([#10507](https://github.com/crystal-lang/crystal/pull/10507), [#10899](https://github.com/crystal-lang/crystal/pull/10899), thanks @HertzDevil)
- Fix error message when default parameter value doesn't match non-type restriction. ([#10515](https://github.com/crystal-lang/crystal/pull/10515), thanks @HertzDevil)
- Fix type restriction logic for generic module instances. ([#10519](https://github.com/crystal-lang/crystal/pull/10519), thanks @HertzDevil)
- Fix logic for subclass restricted against uninstantiated nested generic superclass. ([#10522](https://github.com/crystal-lang/crystal/pull/10522), [#10560](https://github.com/crystal-lang/crystal/pull/10560), thanks @HertzDevil)
- Fix: eliminate extraneous types in certain non-commutative unions. ([#10527](https://github.com/crystal-lang/crystal/pull/10527), thanks @HertzDevil)
- Fix: exclude variables' final types inside `while true` if re-assigned before first break. ([#10538](https://github.com/crystal-lang/crystal/pull/10538), thanks @HertzDevil)
- Make `Pointer(T)#value=` even stricter for generic arguments. ([#10553](https://github.com/crystal-lang/crystal/pull/10553), thanks @HertzDevil)
- Fix body locations for def nodes that have default args . ([#10619](https://github.com/crystal-lang/crystal/pull/10619), thanks @oprypin)
- Fix call nodes' location after transforming its splats. ([#10620](https://github.com/crystal-lang/crystal/pull/10620), thanks @oprypin)
- Fix `check_type_allowed_as_proc_argument` to show the type name. ([#10688](https://github.com/crystal-lang/crystal/pull/10688), thanks @straight-shoota)
- Add free variables to "no overload matches" errors. ([#10692](https://github.com/crystal-lang/crystal/pull/10692), thanks @HertzDevil)
- Fix: make virtual unbound types also unbound. ([#10704](https://github.com/crystal-lang/crystal/pull/10704), thanks @HertzDevil)
- Fix: run instance variable initializers on instantiated generic superclasses only. ([#10729](https://github.com/crystal-lang/crystal/pull/10729), thanks @HertzDevil)
- Fix: allow `previous_def` to init superclass's non-nilable ivars. ([#10733](https://github.com/crystal-lang/crystal/pull/10733), thanks @HertzDevil)
- Fix: Use only last sub-expression of `Expressions` nodes for conditional type filters. ([#10738](https://github.com/crystal-lang/crystal/pull/10738), thanks @HertzDevil)
- Fix: Don't compute type filters inside `typeof`'s argument. ([#10739](https://github.com/crystal-lang/crystal/pull/10739), thanks @HertzDevil)
- Fix: Devirtualize types in `TypeNode#==(other : TypeNode)` and `#!=`. ([#10742](https://github.com/crystal-lang/crystal/pull/10742), thanks @HertzDevil)
- Fix exit types of variables assigned inside `while` conditions. ([#10759](https://github.com/crystal-lang/crystal/pull/10759), thanks @HertzDevil)
- Fix logic for `responds_to?` of generic module instances. ([#10760](https://github.com/crystal-lang/crystal/pull/10760), thanks @HertzDevil)
- Add support for accessing a common value of a union type. ([#10770](https://github.com/crystal-lang/crystal/pull/10770), thanks @asterite)
- Fix subtype relation when generic type variable is a virtual abstract struct. ([#10779](https://github.com/crystal-lang/crystal/pull/10779), thanks @HertzDevil)
- Fix array literals consisting entirely of splat expansions. ([#10792](https://github.com/crystal-lang/crystal/pull/10792), thanks @HertzDevil)
- Fix parsing macro literal containing char literal. ([#10799](https://github.com/crystal-lang/crystal/pull/10799), thanks @straight-shoota)
- Refactor: Use type instead of `is_a?` in filters. ([#10815](https://github.com/crystal-lang/crystal/pull/10815), thanks @caspiano)
- Expand named macro expression arguments before outer macro call expansion. ([#10819](https://github.com/crystal-lang/crystal/pull/10819), thanks @HertzDevil)
- Be more strict about printing operator calls as short forms. ([#10825](https://github.com/crystal-lang/crystal/pull/10825), thanks @HertzDevil)
- Fix union logic between metaclasses of uninstantiated generic classes in same hierarchy. ([#10832](https://github.com/crystal-lang/crystal/pull/10832), thanks @HertzDevil)
- Fix uninstantiated generic classes casting to themselves. ([#10883](https://github.com/crystal-lang/crystal/pull/10883), thanks @HertzDevil)
- Allow underscore in block return type even if the type can't be computed ([#10933](https://github.com/crystal-lang/crystal/pull/10933), thanks @asterite)
- Fix parser identifies call with named args as var ([#10842](https://github.com/crystal-lang/crystal/pull/10842), thanks @straight-shoota)
- Fix: allow trailing space in parenthesized unions. ([#10595](https://github.com/crystal-lang/crystal/pull/10595), thanks @HertzDevil)
- Fix: don't consume newline after endless range literals. ([#10596](https://github.com/crystal-lang/crystal/pull/10596), thanks @HertzDevil)
- Fix indentation of heredocs relative to delimiter. ([#10806](https://github.com/crystal-lang/crystal/pull/10806), thanks @HertzDevil)
- Fix heredoc indent with outer indent. ([#10867](https://github.com/crystal-lang/crystal/pull/10867), thanks @straight-shoota)
- Fix escaping of argument lists in doc generator, expose JSON. ([#10109](https://github.com/crystal-lang/crystal/pull/10109), [#10821](https://github.com/crystal-lang/crystal/pull/10821), thanks @oprypin and @Sija)
- Print named generic type arguments of type restrictions in docs. ([#10424](https://github.com/crystal-lang/crystal/pull/10424), thanks @HertzDevil)
- Fix: respect overload order between methods. ([#10609](https://github.com/crystal-lang/crystal/pull/10609), thanks @HertzDevil)
- Fix `PropagateDocVisitor` visit macro def. ([#10634](https://github.com/crystal-lang/crystal/pull/10634), thanks @straight-shoota)
- Fix: remove superclass from `ASTNode` in API docs. ([#10664](https://github.com/crystal-lang/crystal/pull/10664), thanks @beta-ziliani)
- **(breaking-change)** Remove deprecated `ditto` doc directive. ([#10755](https://github.com/crystal-lang/crystal/pull/10755), thanks @caspiano)
(Note that it was scheduled for removal since 0.34)
- Fix: Restrict macro types' ancestors to `ASTNode`. ([#10722](https://github.com/crystal-lang/crystal/pull/10722), thanks @HertzDevil)
- Fix docs generator search use `html_id`. ([#10875](https://github.com/crystal-lang/crystal/pull/10875), thanks @straight-shoota)
- Fix `--sitemap-priority`, `--sitemap-changefreq`. ([#10906](https://github.com/crystal-lang/crystal/pull/10906), thanks @HertzDevil)
- CI: Update to use 1.0.0. ([#10533](https://github.com/crystal-lang/crystal/pull/10533), thanks @bcardiff)
- Bump distribution-scripts. ([#10639](https://github.com/crystal-lang/crystal/pull/10639), [#10673](https://github.com/crystal-lang/crystal/pull/10673), [#10754](https://github.com/crystal-lang/crystal/pull/10754), thanks @straight-shoota and @bcardiff)
- Fix contribution instructions. ([#10558](https://github.com/crystal-lang/crystal/pull/10558), thanks @straight-shoota)
- Remove `.dockerignore`. ([#10642](https://github.com/crystal-lang/crystal/pull/10642), thanks @miry)
- Add section about pull requests to the contributing guide. ([#10683](https://github.com/crystal-lang/crystal/pull/10683), thanks @straight-shoota)
- Publish nightly builds to OBS. ([#10684](https://github.com/crystal-lang/crystal/pull/10684), thanks @straight-shoota)
- Remove broken travis.yml config from `crystal init`. ([#10800](https://github.com/crystal-lang/crystal/pull/10800), thanks @straight-shoota)
- Disable broken `test_darwin` job on circleci. ([#10823](https://github.com/crystal-lang/crystal/pull/10823), thanks @straight-shoota)
- Update distribution-scripts for shards 0.15.0. ([#10862](https://github.com/crystal-lang/crystal/pull/10862), thanks @straight-shoota)
- Add smoke tests for platforms where we don't run full tests ([#10848](https://github.com/crystal-lang/crystal/pull/10848), thanks @straight-shoota)