diff --git a/contrib/gentoo/games-action/d1x-rebirth/d1x-rebirth-0.59.100.ebuild b/contrib/gentoo/games-action/d1x-rebirth/d1x-rebirth-0.59.100.ebuild
index 8b9063c1d..394965e6b 100644
--- a/contrib/gentoo/games-action/d1x-rebirth/d1x-rebirth-0.59.100.ebuild
+++ b/contrib/gentoo/games-action/d1x-rebirth/d1x-rebirth-0.59.100.ebuild
@@ -16,7 +16,7 @@ DESCRIPTION="Descent Rebirth - enhanced Descent $MY_ENGINE engine"
 HOMEPAGE="http://www.dxx-rebirth.com/"
 SRC_URI=""
 
-LICENSE="D1X GPL-3"
+LICENSE="DXX-Rebirth GPL-3"
 SLOT="0"
 KEYWORDS="amd64 x86"
 IUSE="debug editor ipv6 +opengl timidity tracker"
diff --git a/contrib/gentoo/games-action/descent1-freedata/descent1-freedata-1.ebuild b/contrib/gentoo/games-action/descent1-freedata/descent1-freedata-1.ebuild
new file mode 100644
index 000000000..52598e172
--- /dev/null
+++ b/contrib/gentoo/games-action/descent1-freedata/descent1-freedata-1.ebuild
@@ -0,0 +1,48 @@
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=6
+
+DXX_ENGINE="${PN:7:1}"
+DESCRIPTION="Free content for games-action/d${DXX_ENGINE}x-rebirth"
+HOMEPAGE="http://www.dxx-rebirth.com/"
+IUSE="l10n_de opl3-musicpack sc55-musicpack"
+SRC_URI="
+	l10n_de? ( http://www.dxx-rebirth.com/download/dxx/res/d${DXX_ENGINE}xr-briefings-ger.dxa )
+	opl3-musicpack? ( http://www.dxx-rebirth.com/download/dxx/res/d${DXX_ENGINE}xr-opl3-music.dxa )
+	sc55-musicpack? ( http://www.dxx-rebirth.com/download/dxx/res/d${DXX_ENGINE}xr-sc55-music.dxa )
+"
+
+if [[ "${PN}" = descent1-freedata ]]; then
+	IUSE+=" +textures"
+	SRC_URI+="
+	textures? ( http://www.dxx-rebirth.com/download/dxx/res/d1xr-hires.dxa )
+"
+fi
+
+LICENSE="public-domain"
+SLOT="0"
+KEYWORDS="~amd64 ~x86"
+
+# If all USE flags are unset, this ebuild installs zero files.  Require
+# at least one to be set.
+REQUIRED_USE="|| ( ${IUSE//+/} )"
+
+DEPEND=""
+RDEPEND=""
+
+unset DXX_ENGINE
+
+src_install() {
+	local DXX_ENGINE="${PN:7:1}"
+	insinto /usr/share/games/d${DXX_ENGINE}x
+	use opl3-musicpack && doins "${DISTDIR}"/d${DXX_ENGINE}xr-opl3-music.dxa
+	use sc55-musicpack && doins "${DISTDIR}"/d${DXX_ENGINE}xr-sc55-music.dxa
+	use l10n_de && doins "${DISTDIR}"/d${DXX_ENGINE}xr-briefings-ger.dxa
+
+	# This ebuild is used for both Descent 1 free data and Descent 2
+	# free data.  Only Descent 1 provides alternate textures.
+	if [[ "${PN}" = descent1-freedata ]] && use textures; then
+		insinto /usr/share/games/d1x
+		doins "${DISTDIR}"/d1xr-hires.dxa
+	fi
+}
diff --git a/contrib/gentoo/games-action/descent2-freedata/descent2-freedata-1.ebuild b/contrib/gentoo/games-action/descent2-freedata/descent2-freedata-1.ebuild
new file mode 120000
index 000000000..d0873bf0b
--- /dev/null
+++ b/contrib/gentoo/games-action/descent2-freedata/descent2-freedata-1.ebuild
@@ -0,0 +1 @@
+../descent1-freedata/descent1-freedata-1.ebuild
\ No newline at end of file
diff --git a/contrib/gentoo/games-action/dxx-rebirth/dxx-rebirth-9999.ebuild b/contrib/gentoo/games-action/dxx-rebirth/dxx-rebirth-9999.ebuild
index 29bf58492..803ada14f 100644
--- a/contrib/gentoo/games-action/dxx-rebirth/dxx-rebirth-9999.ebuild
+++ b/contrib/gentoo/games-action/dxx-rebirth/dxx-rebirth-9999.ebuild
@@ -1,3 +1,5 @@
+# Distributed under the terms of the GNU General Public License v2
+#
 # After release 0.58.1 and before beta release 0.59.100, upstream
 # combined the source for the Descent 1 and Descent 2 engines into a
 # single tree.  The combined tree builds common code into a static
@@ -8,7 +10,7 @@
 
 EAPI=6
 
-inherit eutils scons-utils toolchain-funcs
+inherit eutils scons-utils toolchain-funcs xdg
 if [[ "$PV" = 9999 ]]; then
 	inherit git-r3
 	EGIT_REPO_URI="https://github.com/dxx-rebirth/dxx-rebirth"
@@ -20,10 +22,10 @@ else
 	RESTRICT='mirror'
 fi
 
-DESCRIPTION="Descent Rebirth - enhanced Descent engines"
+DESCRIPTION="Descent Rebirth - enhanced Descent 1 & 2 engine"
 HOMEPAGE="http://www.dxx-rebirth.com/"
 
-LICENSE="D1X GPL-3"
+LICENSE="DXX-Rebirth GPL-3"
 SLOT="0"
 # Other architectures are reported to work, but not tested regularly by
 # the core team.
@@ -35,50 +37,122 @@ SLOT="0"
 KEYWORDS="amd64 x86"
 # Default to building both game engines.  The total size is relatively
 # small.
-IUSE="+d1x +d2x debug editor ipv6 +opengl timidity tracker"
+IUSE="+d1x +d2x debug editor +flac ipv6 +joystick l10n_de +midi +mp3 +music +opengl opl3-musicpack sc55-musicpack tracker +vorbis"
 
-DEPEND="opengl? ( virtual/opengl virtual/glu )
-	dev-games/physfs[hog,mvl,zip]
-	media-libs/libsdl[sound,opengl?,video]
-	media-libs/sdl-mixer[timidity?]"
+DEPEND="dev-games/physfs[hog,mvl,zip]
+	media-libs/libsdl[joystick?,opengl?,sound,video]
+	music? ( media-libs/sdl-mixer )
+	opengl? (
+		virtual/opengl
+		virtual/glu )"
+
+# As of this writing, there is no Portage shorthand syntax to express:
+# "
+# 	flag1? ( package[flag1] )
+# 	flag2? ( package[flag2] )
+# 	...
+# 	flagN? ( package[flagN] )
+# ", such that unsetting all flags removes the dependency on package.
+# Fake it by using a text fragment that is repeatedly expanded with
+# differing substitutions.
+#
+# The use of single quotes is intentional here.  The ${word} is a
+# placeholder to be matched by text substitution when the fragment is
+# expanded, not a shell variable reference.
+#
+# For each flag, depend on freedata using the same flag.  If none of the
+# flags are set, freedata is not needed.
+DXX_RDEPEND_USE_FREEDATA_FRAGMENT='
+	${USE}? ( games-action/descent${ENGINE}-freedata[${USE}] )
+'
+# Block <0.59.100 due to file collision.
+#
+# Require game data package.
 # The build process does not use the game data, nor change how the game
 # is built based on what game data will be used.  At startup, the game
 # will search for both types of game data and use what it finds.  Users
 # can switch between shareware/retail data at any time by
 # adding/removing the appropriate data packages.  A rebuild is _not_
 # required after swapping the data files.
+#
+# USE-depend on freedata for various extras, but only if any of those
+# extras are enabled.
+DXX_RDEPEND_ENGINE_FRAGMENT='
+	d${ENGINE}x? (
+		!<games-action/d${ENGINE}x-rebirth-0.59.100
+		|| (
+			games-action/descent${ENGINE}-data
+			games-action/descent${ENGINE}-demodata
+		)
+		'"
+		${DXX_RDEPEND_USE_FREEDATA_FRAGMENT//\$\{USE\}/l10n_de}
+		${DXX_RDEPEND_USE_FREEDATA_FRAGMENT//\$\{USE\}/opl3-musicpack}
+		${DXX_RDEPEND_USE_FREEDATA_FRAGMENT//\$\{USE\}/sc55-musicpack}
+		"'
+	)
+'
+unset DXX_RDEPEND_USE_FREEDATA_FRAGMENT
 RDEPEND="${DEPEND}
-	d1x? (
-		|| (
-			games-action/descent1-data
-			games-action/descent1-demodata
-		)
-	)
-	d2x? (
-		|| (
-			games-action/descent2-data
-			games-action/descent2-demodata
-		)
-	)
+	music? ( media-libs/sdl-mixer[flac?,midi?,mp3?,vorbis?] )
+	${DXX_RDEPEND_ENGINE_FRAGMENT//\$\{ENGINE\}/1}
+	${DXX_RDEPEND_ENGINE_FRAGMENT//\$\{ENGINE\}/2}
 "
+unset DXX_RDEPEND_ENGINE_FRAGMENT
 
 # This ebuild builds d1x-rebirth, d2x-rebirth, or both.  Building none
 # would mean this ebuild installs zero files.
-REQUIRED_USE="|| ( d1x d2x )"
+#
+# For each of the supported music flags, require USE=music, so that the
+# package is built with sdl-mixer support.  Individual music types can be
+# changed without a Rebirth rebuild by rebuilding sdl-mixer with
+# appropriate support, but Rebirth must have sdl-mixer support at build
+# time in order to support any of these music formats at runtime.
+#
+# All music files in the optional musicpack downloads are .ogg, so
+# require USE=vorbis if those packs are enabled.
+REQUIRED_USE='
+	|| ( d1x d2x )
+	flac? ( music )
+	midi? ( music )
+	mp3? ( music )
+	vorbis? ( music )
+	opl3-musicpack? ( vorbis )
+	sc55-musicpack? ( vorbis )
+'
+
+# As of this writing, IUSE_RUNTIME is a GLEP, but not an implemented
+# feature.  This variable is stored here to be ready to activate when
+# Portage implements this feature.
+#
+# Note that while individual music formats can be switched without a
+# rebuild, the master flag USE=music controls whether sdl-mixer is used,
+# and therefore requires a rebuild when changed.
+#IUSE_RUNTIME="flac l10n_de midi mp3 opl3-musicpack sc55-musicpack vorbis"
 
 dxx_scons() {
 	# Always build profile `m`.  If use editor, also build profile `e`.
 	# Set most variables in the default anonymous profile.  Only
 	# `builddir` and `editor` are set in the named profiles, since those
 	# must be different between the two builds.
+	#
+	# Notes for end users:
+	# - Per-engine options can be set with an engine prefix, as shown
+	#   for sharepath.  Such options are used in place of
+	#   engine-unqualified options.  For example, to disable sdlmixer
+	#   for Descent 2: Rebirth, but use the setting below for Descent 1:
+	#   Rebirth, set EXTRA_ESCONS="d2x_sdlmixer=0".
+	# - Profile `site` is searched before the anonymous profile, and is
+	#   deliberately unused in this ebuild.  Set options in the site
+	#   profile to affect both engines:
+	#   EXTRA_ESCONS="site_verbosebuild=0".
 	local scons_build_profile=m mysconsargs=(
-		sdlmixer=1
+		sdlmixer=$(usex music 1 0)
 		verbosebuild=1
 		debug=$(usex debug 1 0)
 		ipv6=$(usex ipv6 1 0)
 		opengl=$(usex opengl 1 0)
 		use_tracker=$(usex tracker 1 0)
-		prefix=/usr
+		prefix="${EPREFIX}"/usr
 		m_builddir=build/main/
 		m_editor=0
 	)
@@ -89,12 +163,17 @@ dxx_scons() {
 			e_editor=1
 		)
 	fi
+	if ! use joystick; then
+		mysconsargs+=(
+			max_joysticks=0
+		)
+	fi
 	# Add sharepath and enable build of selected games.  The trailing
 	# comma after `$scons_build_profile` is required to cause scons to
 	# search the anonymous profile.  If omitted, only settings from the
 	# named profile would be used.
-	use d1x && mysconsargs+=( d1x_sharepath="/usr/share/games/d1x" d1x="$scons_build_profile," )
-	use d2x && mysconsargs+=( d2x_sharepath="/usr/share/games/d2x" d2x="$scons_build_profile," )
+	use d1x && mysconsargs+=( d1x_sharepath="/usr/share/games/d1x" d1x="$scons_build_profile,site," )
+	use d2x && mysconsargs+=( d2x_sharepath="/usr/share/games/d2x" d2x="$scons_build_profile,site," )
 	escons "${mysconsargs[@]}" "$@"
 }
 
@@ -104,5 +183,18 @@ src_compile() {
 }
 
 src_install() {
+	# Use upstream install target to handle the various combinations of
+	# enabled/disabled engines and optional editor support.
 	dxx_scons register_compile_target=0 register_install_target=1 DESTDIR="$D" "$D"
+	local DV
+	for DV in 1 2; do
+		if ! use d${DV}x; then
+			continue
+		fi
+		local PROGRAM=d${DV}x-rebirth
+		docinto "${PROGRAM}"
+		dodoc "${PROGRAM}"/*.txt
+		make_desktop_entry "${PROGRAM}" "Descent ${DV} Rebirth" "${PROGRAM}"
+		doicon "${PROGRAM}/${PROGRAM}.xpm"
+	done
 }