DOOM Retro v1.9 is now available. It may be downloaded here, and its release notes are as follows:

• DOOM Retro now allows the automap to be shown on a second display. This feature may be enabled using the am_external CVAR, and will display a fullscreen 16:10 automap in the first display it finds that is not the main display set by the vid_display CVAR. While this external automap is displayed, the TAB key is disabled, and the iddt cheat can be entered at any time. Also, the automap’s usual controls are unavailable, but the grid and rotate mode may still be toggled in the console using the relevant CVARs.

Alun “Viggles” Bestor’s Cacoward 2015 winner, BREACH.WAD, running on dual screens.
• Optimizations have been made to further improve the overall performance of DOOM Retro.
• A new filter is now available to scale DOOM Retro onto the display. It is enabled by changing the value of the vid_scalefilter CVAR to "nearest_linear", and is a combination of the existing two filters, "nearest" (which uses nearest-neighbor interpolation, the default) and "linear" (which uses linear filtering).
• The screen will no longer “bleed” along the edges when the vid_scaledriver CVAR is set to "" or "direct3d" and the vid_scalefilter CVAR is set to "linear" on some systems.
• A bug has been fixed whereby screenshots couldn’t be taken by pressing the PRINTSCREEN key if characters that can’t be used in a filename were present in the current map’s title.
• A disk icon (the STDISK lump) is now displayed in the top righthand corner of the screen when saving and loading a game, and when loading a map. It may be disabled using the r_diskicon CVAR.
• A nomonsters CCMD has been implemented which will toggle whether monsters are spawned or not in the next map. This CCMD will override when –nomonsters is specified on the command-line.
• The entire screen will now shake when the player is injured. This feature may be disabled using the r_shakescreen CVAR.
• Several improvements have been made to the support of DeHackEd patches and files.
• If a savegame fails to load, the menu will now close and the console will open displaying an error explaining why.
• A crash will no longer occur when trying to open a map that contains only one subsector.
• A bug has been fixed whereby some CVARs weren’t being validated at startup.
• Timestamped obituaries can now be displayed in the console each time something is killed, exploded or resurrected during a game. They are disabled by default, and may be enabled by using the con_obituaries CVAR.
• A bug has been fixed whereby a HOM could appear in maps that use texture 0 as a placeholder.
• Changing the r_liquid_swirl CVAR will now always update visible liquid sectors immediately.
• The darkest of the gradually transitioning lighting under doors is now slightly darker than all adjacent sectors to make the feature more prominent.
• Blood splats are no longer left behind if Lost Souls are close enough to the ground when the kill CCMD is used to kill them.
• nerve.wad will now be recognized correctly when specified using –file on the command-line.
• A bug has been fixed whereby entering a cheat in the console could stop player messages from appearing.
• The iwadfolder CVAR will now be set correctly when more than one PWAD is selected in the WAD launcher.
• Map titles that have been changed using a DeHackEd file or lump will be capitalized as necessary.
• “DOOM RETRO” is now displayed as “DOOM Retro” in all instances.
• The output displayed in the console at startup regarding doomretro.cfg now distinguishes between the file not being present because DOOM Retro is being run for the first time, or because the file is missing.
• Grammar has been fixed in the output in the console when only one lump is present in a PWAD.
• The game will no longer crash when –nosfx or –nosound are specified on the command-line.
• A bug has been fixed whereby floating and bobbing items would get stuck in the floor or ceiling in some instances.
• The error displayed when an invalid +action is passed to the bind CCMD has been fixed.
• Which WAD the COLORMAP is being used from is now output to the console at startup.
• Spacing may now be used in the parameters passed to the kill and spawn CCMDs. For example, spawn baron of hell can be used as well as spawn baronofhell.
• The UK English spelling of “armor” (that is, “armour”) may now be used as the parameter for CCMDs that allow it.
• Entering the kill CCMD without any parameters will no longer kill the player, and instead will display a list of parameters. To kill the player, now use kill player.
• The give CCMD can now also be used to give the player anything that they can pick up during a game. For example, give berserk and give soulsphere.
• The console is now automatically closed when using the give CCMD.
• A bug has been fixed whereby corpses weren’t sliding even when the r_corpses_slide CVAR was on.
• The intensity of the red screen tint when the player has a berserk power-up and their fists up has been reduced slightly.
• The red screen tint when the player is injured, and the gold tint when the player picks up something will now show through while the player has a berserk power-up and their fists up.
• The r_altlighting CVAR has been removed.
• A slight current is now applied to liquid sectors, in a random direction determined at the start of each map. It may be disabled using the r_liquid_current CVAR.
• A bug has been fixed whereby the bottom wall texture between adjacent liquid sectors would show through in some instances.
• The player’s weapon sprite will no jump slightly when switching to and from the automap while moving.
• Although a majority of animated flats in DOOM are liquid, in some PWADs there are some that are not. There are now several instances in some popular PWADs where DOOM Retro’s liquid effects won’t be applied.
• The r_lowpixelsize CVAR will now be correctly parsed at startup.
• The r_lowpixelsize CVAR can now be set to values of 2×1 and 1×2.
• The amount of blood splats spawned when corpses slide along the ground has been halved to 256.
• A bug has been fixed whereby generalized floors could become stuck after loading a savegame.
• The help screen has been updated to show that the ~ key opens the console.
• All instances of “DOOM” and “DOOM Retro” that appear in the console and the splash screen have been italicized.
• If an IWAD is specified on the command-line using –iwad but with no path, DOOM Retro will now check for an installation of DOOM purchased through GOG.com.
• If a PWAD file is loaded, savegames are now separated based on that file, rather than the IWAD file. (Because of this, and also because a change in how the folders savegames are saved into are named, savegames from previous versions of DOOM Retro will no longer appear in the save and load game menus.)
• The savegamefolder CVAR has been removed. Instead, the folder savegames are saved to and loaded from is displayed in the console at startup.
• A bug has been fixed whereby if the player died in a sector with special 11, they would appear in the next map with zero health and be unable to pick up items or alert enemies.
• The default mouse sensitivity has been increased from 16 to 24.
• Shadows are now opaque when the r_translucency CVAR is off.
• The pitch of the player’s sounds is no longer randomized when the s_randompitch CVAR is on.
• Generalized linedefs without tags are now applied locally, rather than not working at all.
• The positions that blood splats are spawned are now more accurate when blood falls to the ground.
• The % symbol will no longer disappear from the end of the pm_walkbob CVAR’s value.
• The CVAR names will no longer be shown when entering the gp_deadzone_left or gp_deadzone_right CVARs to display their values.
• DOOM Retro will now play MP3 and Ogg Vorbis music lumps. This requires the files libogg-0.dll, libvorbis-0.dll, libvorbisfile-3.dll and smpeg2.dll all to be in the same folder as doomretro.exe.
• A warning is now displayed in the console when a music lump can’t be played.
• Tilde characters are now removed from the files saved using the condump CCMD.