OpenTTD v15.0-beta1 is released. OpenTTD is an open source simulation game based upon the popular Microprose game "Transport Tycoon Deluxe", written by Chris Sawyer. It attempts to mimic the original game as closely as possible while extending it with new features.

Features
OpenTTD is modelled after the original Transport Tycoon game by Chris Sawyer and enhances the game experience dramatically. Many features were inspired by TTDPatch while others are original.

Significant enhancements from the original game include:
bigger maps (up to 64 times in size)
stable multiplayer mode for up to 255 players in 15 companies, or as spectators
dedicated server mode and an in-game console for administration
IPv6 and IPv4 support for all communication of the client and server
in game downloading of AIs, NewGRFs, scenarios and heightmaps
new pathfinding algorithms that makes vehicles go where you want them to
autorail/-road build tool, improved terraforming
canals, shiplifts, aqueducts
larger, non-uniform stations and the ability to join them together
mammoth and multi-headed trains
different configurable models for acceleration of vehicles
clone, autoreplace and autoupdate vehicles
the possibility to build on slopes and coasts
advanced/conditional orders, share and copy orders
longer and higher bridges including several new designs, plus fully flexible tracks/roads under bridges
reworked airport system with many more airports/heliports (e.g. international and metropolitan)
presignals, semaphores, path based signalling
support for TTDPatch NewGRF features offering many options for graphics and behaviour configuration/modification
drive-through road stops for articulated road vehicles and trams
multiple trees on one tile
bribe the town authority
many configuration settings to tune the game to your liking
save games using zlib compression for smaller sizes, while not interrupting gameplay
significant internationalisation support. OpenTTD has already been translated into over 50 languages
dynamically created town names in 18 languages, plus NewGRF support for additional languages
freely distributable graphics, sounds and music
framework for custom (user) written AIs
zooming further out in the normal view and zooming out in the small map
Lots of effort has been put into making OpenTTD easy to use. These include:

convert rail tool (to electrified rail, monorail, and maglev)
drag&drop support for almost all tools (demolition, road/rail building/removing, stations, scenario editor, etc)
sorting of most lists based on various criteria (vehicle, station, town, industries, etc.)
mouse wheel support (scroll menus, zoom in/out)
autoscroll when the mouse is near the edge of the screen/window
sell whole train by dragging it to the dynamite trashcan
cost estimation with the 'shift' key
advanced options configuration window, change settings from within the game
Graphical/interface features:

screenshots can be in BMP, PNG or PCX format (select in game options menu)
more currencies (including Euro introduction in 2002)
extra viewports to view more parts of the game world at the same time
resolution and refresh rate selection for fullscreen mode
colourful newspaper after a certain date
colour coded vehicle profits
game speed increase (through fast forward button or by pressing the TAB key)
snappy and sticky windows that always stay on top and neatly align themselves to other windows
more hotkeys for even less mouse-clicking
support for 32 bit graphics
support for right-to-left languages
support for other (sized) fonts where the user interface scales based on the font and translation

OpenTTD Changelog:
- Feature: Town, industry and vehicle window zoom with mouse wheel (#12810, #12809, #12797)
- Feature: Show count of towns and industries in their directory window captions (#12800)
- Feature: Toggle for showing industry names in small map (#12770)
- Feature: Manually place town buildings in scenario editor (#12661, #12741)
- Feature: Filter new picker window by all classes, by used types, or by favourites (#12595)
- Feature: New picker window for rail and road stations, rail and road waypoints, and objects (#12595)
- Feature: Road waypoints (#12572)
- Feature: Allow base sounds set to be changed mid-game (#12399)
- Feature: Authorize specific clients to join network, company and remote console without password (#12337, #12326, #12329)
- Feature: Authenticate to the server without sending the password (#12323, #11878)
- Feature: Encrypt the connection between game server and client, and admin (#12300, #11878)
- Feature: Industry production/transported graph (#10541, #13083)
- Feature: Import town data from JSON file (#10409)
- Add: Implement 2D map scrolling under SDL2 (#13169)
- Add: [NewGRF] Callback for custom refit mask for engines/vehicles (#13090)
- Add: [NewGRF] Vehicle prop that allows refittability based on cargo class intersection (#13090)
- Add: Ability to show and filter different datasets on the same graph (#13083)
- Add: Show and toggle follow vehicle state in vehicle view window (#13076)
- Add: Set application name for SDL2 (#13061)
- Add: Support sound effects in Ogg Opus format (#13055)
- Add: Improving town-owned bridges increases company rating (#13036)
- Add: Apply rail/road type conversion when NewGRFs are updated mid-game (#13021)
- Add: Implement missing road type label conversion (#13021)
- Add: [NewGRF] Cargo class bits 13 and 14 now define potable and non-potable (#12979)
- Add: Overlay cargo icon in vehicle/depot list when holding shift+ctrl (#12938)
- Add: [Script] Include number of victims in ScriptEventVehicleCrashed (#12861)
- Add: [Console] Schedule command to execute a script file next in-game month (#12761)
- Add: Setting to disable warning for old vehicles (#12714)
- Add: Use macOS Game Mode identification (#12700)
- Add: Shade button to waypoint picker (#12682)
- Add: [NewGRF] Extended custom waypoint classes (#12653)
- Add: 'Get Content' buttons next to base set dropdowns in Game Options (#12627)
- Add: [NewGRF] Custom road waypoint support (#12572)
- Add: [NewGRF] Allow fixed layout up to 256 tiles per NewGRF rail station (#12554)
- Add: [NewGRF] Station property 1E, extended station tile flags (#12554)
- Add: [SDL2] Driver parameter 'no_mouse_capture' to ease interactive debugging (#12336)
- Add: Basic autocompletion on tab for console commands (#12163)
- Add: Portuguese Escudo currency (#12108)
- Change: Hide buttons in Found Town window that can't be used (#13182)
- Change: Include new cargo classes in dump cargo types console command (#13174)
- Change: Use floats for tracking 2D scrolling to improve smoothness (#13169)
- Change: Improve news window layouts (#13136, #13134)
- Change: Show company finances column if it has any values in it (#13112)
- Change: Treat recolour sprites as regular sprites in the SpriteCache (#13107)
- Change: Determine industry directory width only on visible rows (#13097)
- Change: Add sound memory usage to framerate window (#13055)
- Change: Invalidate build toolbars when NewGRFs are changed (#13046)
- Change: Don't try to flood buoys or dock tiles (#13013)
- Change: Store water tile flooding state in the map (#13013)
- Change: Exclude parent item from directory sort in FiosGetFileList (#12947)
- Change: [NewGRF] Place all 8 bits of station tile layout in var 40/41 (#12890)
- Change: [NewGRF] Install translation tables into overridden NewGRF (#12879)
- Change: [UI] Use scaled sprite sizes and correct matrix padding for content list (#12875)
- Change: [UI] Improved Network server list icon sizing and text positioning (#12874)
- Change: Path signals now show green on junction-less tracks by default (#12857)
- Change: Don't use house construction states in Scenario Editor (#12822)
- Change: Changing zoom no longer stops following vehicle (#12808)
- Change: Allow bribing local authority when other company has exclusive rights (#12763)
- Change: Position caret on left or right of glyph depending on language direction (#12760)
- Change: Do not automatically connect double depots with track (#12752)
- Change: Call custom house name callback in House Picker (#12741)
- Change: [NewGRF] Treat house max year 0xFFFF as MAX_YEAR (#12740)
- Change: [UI] Remove substitution of missing glyph with '?' glyph (#12736)
- Change: [UI] Use SetMinimalTextLines to set label height correctly (#12734)
- Change: Don't use house construction states in Scenario Editor (#12730)
- Change: Ignore min/max years for manual house placer (#12687)
- Change: Use default NewGRF cargo translation table if no custom table is provided (#12646)
- Change: Don't include midi file processing in dedicated server build (#12632)
- Change: [Linkgraph] Improve distance scaling algorithm in demand scaler (#12542)
- Change: Draw group hierarchy tree lines (#12522)
- Change: Display more useful information in sprite aligner than sprite ID (#12439)
- Change: Disallow using Action A to load sprites above the baseset unless reserved (#12435)
- Change: Use aspect ratios for some common widgets and buttons (#12386, #12636)
- Change: Show correct default value and unit for vehicle service interval setting (#12376)
- Change: Use per-company group numbers (#12297)
- Change: [NewGRF] Increase house type limit from 512 to 4096 (#12288)
- Change: Add dividers in vehicle group action dropdown (#12284)
- Change: Use same audio buffer size (and config parameter) for all sound drivers (#12227)
- Change: Allow rail and road depot overbuilding in current orientation in order to connect to rail or road (#12219)
- Change: Show tile index as decimal number in land info window (#12104)
- Change: Increase object/station/roadstop class limit (#12094)
- Change: Disable the insecure admin login by default; replaced by allow list (#11878)
- Fix: [NewGRF] New engines did not have a default cargo type set (#13146)
- Fix: String parameter not set when determining width of smallmap contour labels (#13145)
- Fix #13022: Ensure minimum size of scrollbar slider (#13119)
- Fix #13110: [Script] Convert table keys to string when generating JSON (#13113)
- Fix: Error message not set when unable load an old save (#13106)
- Fix: Network clients incorrectly truncated all strings to NETWORK_COMPANY_NAME_LENGTH (#13102)
- Fix: Don't allow right-click to close world generation progress window (#13084)
- Fix: VF_LOADING_FINISHED and VF_STOP_LOADING flags tested on wrong vehicle part (#13063)
- Fix: X-axis direction of industry production graph (#13062)
- Fix #13053: Payment transfers incorrect for non-passenger cargos (#13054)
- Fix: Invalid data used for height map curves after first run (#13039)
- Fix: SkipGarbage() skipped all multi-byte utf-8 characters (#13032)
- Fix: Don't invalidate water regions on the other side of the map (#13012)
- Fix: ScriptTile::PlantTreeRectangle does not check that the end tile is in bounds (#13004)
- Fix #12973: Don't exclude high score after using sandbox (#12999)
- Fix #12976: Incorrect widget rect scrolling for RTL languages (#12978)
- Fix: Crash when exiting game with end game window open (#12962)
- Fix #12957: 1-in-X proportion of towns being cities is unnecessarily random (#12960)
- Fix: ICUParagraphLayout line wrapping (#12956)
- Fix: Highscore/Endgame window can disappear offscreen if game window is resized (#12951)
- Fix #12940: Use specific error when overbuilding station on signals (#12943)
- Fix #12917: Write to negative array index for some string patterns (#12932)
- Fix: Incorrect truncation in string setting validation (#12924)
- Fix #12914: Fix use of invalidated pointer in viewport drawer (#12918)
- Fix: Train curve detection did not take shortened parts into account (#12910)
- Fix: DepotWindow::GetVehicleFromDepotWndPt not refreshing vehicle list (#12907)
- Fix: DupSprite did not copy the control_flags field (#12906)
- Fix: Excessively fast ships on aqueducts fail to move at correct speed (#12895)
- Fix: Timetable does not show vehicles as early (#12873)
- Fix #12856: Updating network settings does not invalidate data (#12858)
- Fix #12839: Truncated help text dialog on Windows (#12844)
- Fix #12832: Sanitise strings from NewGRF before logging them in Debug output (#12835)
- Fix #12825: Crash when opening road toolbar in scenario editor (#12826)
- Fix #12818: During Hostile Takeover, profit was calculated incorrectly (#12819)
- Fix: Apply widget's internal padding to scrollbar capacity/position (#12801)
- Fix #12365: Company Window now displays proper inauguration year and period while in wallclock mode (#12798)
- Fix #12787: Boostrap doesn't have main vindow (#12788)
- Fix #10239: Use elevated snow height for roads on flat foundations (#12776)
- Fix #12764: Crash when opening Detailed performance rating window with no companies (#12765)
- Fix: Water infrastructure total when changing owner of object on water or using DC_FORCE_CLEAR_TILE (#12757, #12729)
- Fix: Editbox behaved improperly with RTL languages (#12746)
- Fix #12283: Vehicle group dropdown shouldn't have default action (#12727)
- Fix: Reverse left/right keypress when editing RTL text (#12711, #12710)
- Fix: Crash if interface scale or font size changes with chat box present (#12705)
- Fix: Make progress bars obey language direction (#12704)
- Fix #12681: Abstract filetype not set for network client join savegames (#12701)
- Fix: Implement support for secure state coding on macOS (#12698)
- Fix: Add entitlements needed for plugins on macOS (#12697)
- Fix: Allow resolving house parent scope (town) of unbuilt houses (#12695)
- Fix #12685: Nullptr dereference when checking for equal loaded/loading groups (#12686)
- Fix: Unable to choose a font containing hyphen (#12684)
- Fix: [Timetable] Use days as precision in day mode for accurate timetable syncing (#12683)
- Fix #12550: Files were not saved in the right location when binary and configuration are in the same folder (#12679)
- Fix #12591: Give descriptive error when station construction fails due to wrong layout (#12678)
- Fix #12594: Give descriptive error when company takeover fails due to vehicle limit (#12676)
- Fix: Ensure revision mismatch also considers random debugging status (#12673)
- Fix #12411: [Admin] Send Network Welcome Packet to admin port after game creation completed WelcomeAll moved into NetworkOnGameStart (#12672)
- Fix: [MacOS] Memory leak in CoreTextFontCache (#12662)
- Fix: Use widget resize step instead of window resize step (#12659)
- Fix #12563: Race condition setting finish flag in WinHTTP (#12658)
- Fix #12648: Ensure all uses of std::filesystem::path use native encoding (#12650)
- Fix #12643: _is_water_region_valid is not cleared/reset in AllocateWaterRegions (#12649)
- Fix: Console command scrolling did not take account of padding and cursor width (#12642)
- Fix: Allow changing size of default OpenTTD font (#12641)
- Fix: Always allow setting company settings, company/president name/face (#12635)
- Fix: For GUI network servers, name the first company the same as any other company (#12629)
- Fix: Properly test for presence of waypoint in NewGRF resolver (#12579)
- Fix: Inconsistent space between console history and current line (#12528)
- Fix: Build industry window did not take width of count into account (#12476)
- Fix: Draw continuation lines for engine variant hierarchy tree (#12434)
- Fix: Viewport signs assume small font is smaller than normal font (#12422)
- Fix #11345: Use correct default button value for vehicle service interval setting (#12376)
- Fix #7982: Show existing coverage with unambiguous adjacent station (#12346)
- Fix: Off-by-one in EnsureVisibleCaption (#12261)
- Fix #11055: Make saveload failure error messages consistent with others (#12247)
- Fix: Train running sounds should only be produced for engine parts (#12229)
- Fix: Maximum permitted sound volume from NewGRF is 128 (#12222)
- Fix: Relocate main toolbar and statusbar before other windows (#12218)
- Fix: YAPF doesn't check destination for start nodes (#12217)
- Fix: Make link graph node borders scale with GUI (#12167)
- Fix #10490: Allow ships to exit depots if another is not moving at the exit point (#12161)
- Fix: Incorrect padding for text purchase list (#12160)
- Fix: GetNextDecisionNode ignored go to nearest depot when combined with stop at depot (#12130)
- Fix: Aircraft could route to hangars outside their range when stopping at them (#12130)
- Remove: Hidden setting for adjacent stations (#12862)
- Remove: Custom opendir implementation for Windows no longer needed (#12524)
- Remove: Company passwords; replaced by client allow lists (#12337)
- Remove: Autoclean_unprotected settings; all companies will be protected (#12337)
- Remove: NPF and pathfinder change settings (#12209)

Download: OpenTTD v15.0-beta1
Source: Here