diff --git a/annotations/build.xml b/annotations/build.xml
deleted file mode 100644
index 5da9ad30..00000000
--- a/annotations/build.xml
+++ /dev/null
@@ -1,51 +0,0 @@
-<!-- Ant build script for the ProGuard annotations. -->
-
-<project name    = "annotations"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir   = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "compile" depends = "out">
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "false"
-           source            = "${target}"
-           target            = "${target}"
-           srcdir            = "src"
-           destdir           = "out"
-           includes          = "proguard/annotation/*.java">
-      <compilerarg value = "-Xlint:none"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "proguard/*.properties"/>
-        <include name = "proguard/*.png"/>
-        <include name = "proguard/*.gif"/>
-        <include name = "proguard/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile  = "../lib/annotations.jar"
-         basedir  = "out"/>
-  </target>
-
-</project>
diff --git a/annotations/makefile b/annotations/makefile
deleted file mode 100644
index ef2ce97c..00000000
--- a/annotations/makefile
+++ /dev/null
@@ -1,7 +0,0 @@
-# GNU/Linux makefile for the ProGuard annotations.
-
-MAIN_CLASS = proguard/annotation/*
-CLASSPATH  =
-TARGET     = annotations
-
-include ../buildscripts/functions.mk
diff --git a/ant/build.xml b/ant/build.xml
deleted file mode 100644
index 7ba180b5..00000000
--- a/ant/build.xml
+++ /dev/null
@@ -1,60 +0,0 @@
-<!-- Ant build script for the ProGuard Ant task. -->
-
-<project name    = "ant"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-  <property file = "ant.properties"/>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "base">
-    <ant dir        = "../base"
-         target     = "compile"
-         inheritAll = "false"/>
-  </target>
-
-  <target name = "compile" depends = "out,base">
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "true"
-           source            = "${target}"
-           target            = "${target}"
-           classpath         = "../base/out:../core/out"
-           srcdir            = "src"
-           destdir           = "out"
-           includes          = "proguard/ant/ProGuardTask.java">
-      <compilerarg value = "-Xlint:none"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "**/*.properties"/>
-        <include name = "**/*.png"/>
-        <include name = "**/*.gif"/>
-        <include name = "**/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile = "../lib/proguard.jar"
-         update  = "true"
-         basedir = "out"/>
-  </target>
-
-</project>
diff --git a/ant/makefile b/ant/makefile
deleted file mode 100644
index 9efa00d2..00000000
--- a/ant/makefile
+++ /dev/null
@@ -1,15 +0,0 @@
-# GNU/Linux makefile for the ProGuard Ant task.
-
-ifndef ANT_HOME
-ANT_HOME = /usr/local/java/ant
-endif
-
-MAIN_CLASS = proguard/ant/ProGuardTask
-ANT_JAR    = $(ANT_HOME)/lib/ant.jar
-CLASSPATH  = ../base/$(OUT):../core/$(OUT):$(ANT_JAR)
-TARGET     = proguard
-UPDATE_JAR = true
-
-include ../buildscripts/functions.mk
-
-$(ANT_JAR): ; $(error Please make sure ANT_HOME is set correctly)
diff --git a/base/ant.properties b/base/ant.properties
deleted file mode 100644
index a6eec343..00000000
--- a/base/ant.properties
+++ /dev/null
@@ -1,3 +0,0 @@
-# Ant build properties for ProGuard.
-
-gson.version = 2.8.5
diff --git a/base/build.xml b/base/build.xml
deleted file mode 100644
index 0e4e8537..00000000
--- a/base/build.xml
+++ /dev/null
@@ -1,67 +0,0 @@
-<!-- Ant build script for ProGuard. -->
-
-<project name    = "base"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-  <property file = "ant.properties"/>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir   = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "download" depends = "lib">
-    <get src          = "https://jcenter.bintray.com/com/google/code/gson/gson/2.8.5/gson-${gson.version}.jar"
-         dest         = "../lib/gson-${gson.version}.jar"
-         skipexisting = "true"/>
-  </target>
-
-  <target name = "core">
-    <ant dir        = "../core"
-         target     = "compile"
-         inheritAll = "false"/>
-  </target>
-
-  <target name = "compile" depends = "out,download,core">
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "false"
-           source            = "${target}"
-           target            = "${target}"
-           srcdir            = "src"
-           destdir           = "out"
-           classpath         = "../core/out:../lib/gson-${gson.version}.jar"
-           includes          = "proguard/ProGuard.java">
-      <compilerarg value = "-Xlint:none"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "proguard/*.properties"/>
-        <include name = "proguard/*.png"/>
-        <include name = "proguard/*.gif"/>
-        <include name = "proguard/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile  = "../lib/proguard.jar"
-         update   = "true"
-         manifest = "src/META-INF/MANIFEST.MF"
-         basedir  = "out"/>
-  </target>
-
-</project>
diff --git a/base/makefile b/base/makefile
deleted file mode 100644
index ae5c1396..00000000
--- a/base/makefile
+++ /dev/null
@@ -1,23 +0,0 @@
-# GNU/Linux makefile for ProGuard.
-
-GSON_VERSION = 2.8.5
-GSON_URL     = https://jcenter.bintray.com/com/google/code/gson/gson/$(GSON_VERSION)/gson-${GSON_VERSION}.jar
-GSON_JAR     = $(LIB)/gson-$(GSON_VERSION).jar
-
-KOTLIN_VERSION           = 1.3.31
-KOTLIN_STDLIB_JAR        = $(LIB)/kotlin-stdlib-$(KOTLIN_VERSION).jar
-KOTLIN_STDLIB_COMMON_JAR = $(LIB)/kotlin-stdlib-common-$(KOTLIN_VERSION).jar
-
-KOTLINX_METADATA_VERSION = 0.1.0
-KOTLINX_METADATA_JVM_JAR = $(LIB)/kotlinx-metadata-jvm-$(KOTLINX_METADATA_VERSION).jar
-
-MAIN_CLASS       = proguard/ProGuard
-CLASSPATH        = ../core/$(OUT):$(GSON_JAR):$(KOTLIN_STDLIB_JAR):$(KOTLIN_STDLIB_COMMON_JAR):$(KOTLINX_METADATA_JVM_JAR)
-TARGET           = proguard
-UPDATE_JAR       = true
-INCLUDE_MANIFEST = true
-
-include ../buildscripts/functions.mk
-
-$(GSON_JAR):
-	$(DOWNLOAD) $(GSON_JAR) $(GSON_URL)
diff --git a/buildscripts/ant.properties b/buildscripts/ant.properties
deleted file mode 100644
index 8047c796..00000000
--- a/buildscripts/ant.properties
+++ /dev/null
@@ -1,3 +0,0 @@
-# Ant build properties for ProGuard.
-
-target = 1.8
diff --git a/buildscripts/build.xml b/buildscripts/build.xml
deleted file mode 100644
index 07c5fd84..00000000
--- a/buildscripts/build.xml
+++ /dev/null
@@ -1,49 +0,0 @@
-<!-- Ant build script for ProGuard. -->
-
-<project name    = "proguard"
-         default = "all"
-         basedir = "..">
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir      = "lib"
-               includes = "*.jar"/>
-    </delete>
-  </target>
-
-  <target name    = "all"
-          depends = "core,base,retrace,gui,gradle,ant,wtk,annotations"/>
-
-  <target name = "core">
-    <ant dir = "core"/>
-  </target>
-
-  <target name = "base">
-    <ant dir = "base"/>
-  </target>
-
-  <target name = "retrace">
-    <ant dir = "retrace"/>
-  </target>
-
-  <target name = "gui">
-    <ant dir = "gui"/>
-  </target>
-
-  <target name = "gradle">
-    <ant dir = "gradle"/>
-  </target>
-
-  <target name = "ant">
-    <ant dir = "ant"/>
-  </target>
-
-  <target name = "wtk">
-    <ant dir = "wtk"/>
-  </target>
-
-  <target name = "annotations">
-    <ant dir = "annotations"/>
-  </target>
-
-</project>
diff --git a/buildscripts/functions.mk b/buildscripts/functions.mk
deleted file mode 100644
index ac0a0a2b..00000000
--- a/buildscripts/functions.mk
+++ /dev/null
@@ -1,76 +0,0 @@
-# Support functions for building ProGuard with make.
-
-SRC = src
-OUT = out
-LIB = ../lib
-
-JAVA_TARGET = 1.8
-
-ifeq ($(CLASSPATH),)
-  CLASSPATH_OPTION =
-else
-  CLASSPATH_OPTION = -classpath $(CLASSPATH)
-endif
-
-TARGET_JAR = $(LIB)/$(TARGET).jar
-
-# Command to download dependencies.
-
-DOWNLOAD = wget -O
-#DOWNLOAD = curl -L -o
-
-# Functions to find the class files and resource files of a given target.
-
-define CLASS_FILES
-  $(subst .java,.class,$(shell find $(SRC)/$(dir $(1)) -path "$(SRC)/$(MAIN_CLASS).java" -printf $(OUT)/$(dir $(1))%P\\n))
-endef
-
-define RESOURCES
-  $(shell find $(SRC)/$(dir $(1)) -maxdepth 1 \( -name \*.properties -o -name \*.png -o -name \*.gif -o -name \*.pro \) -printf $(OUT)/$(dir $(1))%P\\n)
-endef
-
-# Rules for creating the jars.
-
-all: $(TARGET_JAR)
-
-$(TARGET_JAR): $(call CLASS_FILES,$(MAIN_CLASS)) $(LIB)
-ifeq ($(UPDATE_JAR),true)
-ifeq ($(INCLUDE_MANIFEST),true)
-	jar -ufm $@ $(SRC)/META-INF/MANIFEST.MF -C $(OUT) $(dir $(MAIN_CLASS))
-else
-	jar -uf  $@                             -C $(OUT) $(dir $(MAIN_CLASS))
-endif
-else
-ifeq ($(INCLUDE_MANIFEST),true)
-	jar -cfm $@ $(SRC)/META-INF/MANIFEST.MF -C $(OUT) $(dir $(MAIN_CLASS))
-else
-	jar -cf  $@                             -C $(OUT) $(dir $(MAIN_CLASS))
-endif
-endif
-
-$(TARGET_JAR): $(call RESOURCES,$(MAIN_CLASS))
-
-# Rule for compiling the class files.
-
-$(OUT)/%.class: $(OUT) $(SRC)/%.java $(subst :, ,$(CLASSPATH))
-	javac -nowarn -Xlint:none $(CLASSPATH_OPTION) -source $(JAVA_TARGET) -target $(JAVA_TARGET) -sourcepath $(SRC) -d $(OUT) $(filter %.java,$^) 2>&1 | sed -e 's|^|  |'
-
-# Rule for copying the resource files.
-
-$(OUT)/%.properties $(OUT)/%.png $(OUT)/%.gif $(OUT)/%.pro:
-	cp $(subst $(OUT),$(SRC),$@) $@
-
-# Rule for creating output directories.
-
-$(OUT) $(LIB):
-	mkdir -p $@
-
-# Rule for dependencies on other modules.
-
-../%/$(OUT):
-	cd $(dir $@) && $(MAKE)
-
-clean:
-	rm -fr $(OUT)
-
-.PHONY: all clean
diff --git a/buildscripts/makefile b/buildscripts/makefile
deleted file mode 100644
index f91e803f..00000000
--- a/buildscripts/makefile
+++ /dev/null
@@ -1,22 +0,0 @@
-# GNU/Linux makefile for ProGuard.
-
-BASIC_MODULES    = core base retrace gui annotations
-OPTIONAL_MODULES = gradle ant wtk
-
-MODULES = $(BASIC_MODULES) $(OPTIONAL_MODULES)
-
-LIB = ../lib
-
-# The main targets.
-
-all:      basic optional
-basic:    $(BASIC_MODULES)
-optional: $(OPTIONAL_MODULES)
-
-$(MODULES):
-	cd ../$@ && $(MAKE)
-
-clean:
-	rm -fr $(LIB)
-
-.PHONY: all basic optional $(MODULES) clean
diff --git a/core/ant.properties b/core/ant.properties
deleted file mode 100644
index d6ffd95d..00000000
--- a/core/ant.properties
+++ /dev/null
@@ -1,4 +0,0 @@
-# Ant build properties for ProGuard.
-
-kotlin.version           = 1.3.31
-kotlinx.metadata.version = 0.1.0
diff --git a/core/build.xml b/core/build.xml
deleted file mode 100644
index d287e349..00000000
--- a/core/build.xml
+++ /dev/null
@@ -1,64 +0,0 @@
-<!-- Ant build script for ProGuard. -->
-
-<project name    = "core"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-  <property file = "ant.properties"/>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir   = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "download" depends = "lib">
-    <get src          = "https://jcenter.bintray.com/org/jetbrains/kotlin/kotlin-stdlib/${kotlin.version}/kotlin-stdlib-${kotlin.version}.jar"
-         dest         = "../lib/kotlin-stdlib-${kotlin.version}.jar"
-         skipexisting = "true"/>
-    <get src          = "https://jcenter.bintray.com/org/jetbrains/kotlin/kotlin-stdlib-common/${kotlin.version}/kotlin-stdlib-common-${kotlin.version}.jar"
-         dest         = "../lib/kotlin-stdlib-common-${kotlin.version}.jar"
-         skipexisting = "true"/>
-    <get src          = "https://jcenter.bintray.com/org/jetbrains/kotlinx/kotlinx-metadata-jvm/${kotlinx.metadata.version}/kotlinx-metadata-jvm-${kotlinx.metadata.version}.jar"
-         dest         = "../lib/kotlinx-metadata-jvm-${kotlinx.metadata.version}.jar"
-         skipexisting = "true"/>
-  </target>
-
-  <target name = "compile" depends = "out,download">
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "false"
-           source            = "${target}"
-           target            = "${target}"
-           srcdir            = "src"
-           destdir           = "out"
-           classpath         = "../lib/kotlin-stdlib-${kotlin.version}.jar:../lib/kotlin-stdlib-common-${kotlin.version}.jar:../lib/kotlinx-metadata-jvm-${kotlinx.metadata.version}.jar">
-      <compilerarg value = "-Xlint:none"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "proguard/*.properties"/>
-        <include name = "proguard/*.png"/>
-        <include name = "proguard/*.gif"/>
-        <include name = "proguard/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile  = "../lib/proguard.jar"
-         basedir  = "out"/>
-  </target>
-
-</project>
diff --git a/core/makefile b/core/makefile
deleted file mode 100644
index 88fecbf7..00000000
--- a/core/makefile
+++ /dev/null
@@ -1,27 +0,0 @@
-# GNU/Linux makefile for ProGuard.
-
-KOTLIN_VERSION    = 1.3.31
-KOTLIN_STDLIB_URL = https://jcenter.bintray.com/org/jetbrains/kotlin/kotlin-stdlib/$(KOTLIN_VERSION)/kotlin-stdlib-${KOTLIN_VERSION}.jar
-KOTLIN_STDLIB_JAR = $(LIB)/kotlin-stdlib-$(KOTLIN_VERSION).jar
-
-KOTLIN_STDLIB_COMMON_URL = https://jcenter.bintray.com/org/jetbrains/kotlin/kotlin-stdlib-common/$(KOTLIN_VERSION)/kotlin-stdlib-common-${KOTLIN_VERSION}.jar
-KOTLIN_STDLIB_COMMON_JAR = $(LIB)/kotlin-stdlib-common-$(KOTLIN_VERSION).jar
-
-KOTLINX_METADATA_VERSION = 0.1.0
-KOTLINX_METADATA_JVM_URL = https://jcenter.bintray.com/org/jetbrains/kotlinx/kotlinx-metadata-jvm/$(KOTLINX_METADATA_VERSION)/kotlinx-metadata-jvm-${KOTLINX_METADATA_VERSION}.jar
-KOTLINX_METADATA_JVM_JAR = $(LIB)/kotlinx-metadata-jvm-$(KOTLINX_METADATA_VERSION).jar
-
-MAIN_CLASS = proguard/*
-CLASSPATH  = $(KOTLIN_STDLIB_JAR):$(KOTLIN_STDLIB_COMMON_JAR):$(KOTLINX_METADATA_JVM_JAR)
-TARGET     = proguard
-
-include ../buildscripts/functions.mk
-
-$(KOTLIN_STDLIB_JAR):
-	$(DOWNLOAD) $(KOTLIN_STDLIB_JAR) $(KOTLIN_STDLIB_URL)
-
-$(KOTLIN_STDLIB_COMMON_JAR):
-	$(DOWNLOAD) $(KOTLIN_STDLIB_COMMON_JAR) $(KOTLIN_STDLIB_COMMON_URL)
-
-$(KOTLINX_METADATA_JVM_JAR):
-	$(DOWNLOAD) $(KOTLINX_METADATA_JVM_JAR) $(KOTLINX_METADATA_JVM_URL)
diff --git a/gradle/ant.properties b/gradle/ant.properties
deleted file mode 100644
index 46c9d1ea..00000000
--- a/gradle/ant.properties
+++ /dev/null
@@ -1,3 +0,0 @@
-# Ant build properties for the ProGuard Gradle task.
-
-gradle.home = /usr/local/java/gradle
diff --git a/gradle/build.xml b/gradle/build.xml
deleted file mode 100644
index 91a6ae93..00000000
--- a/gradle/build.xml
+++ /dev/null
@@ -1,75 +0,0 @@
-<!-- Ant build script for the ProGuard Gradle task. -->
-
-<project name    = "gradle"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-  <property file = "ant.properties"/>
-
-  <path id="gradle.path">
-    <fileset dir="${gradle.home}/lib">
-      <include name="gradle-core-?.*.jar"/>
-      <include name="gradle-core-api-*.jar"/>
-      <include name="gradle-base-services-?.*.jar"/>
-      <include name="gradle-base-services-groovy-*.jar"/>
-      <include name="gradle-logging-*.jar"/>
-      <include name="gradle-model-base-*.jar"/>
-      <include name="plugins/gradle-plugins-*.jar"/>
-      <include name="groovy-all-*.jar"/>
-      <include name="slf4j-api-*.jar"/>
-    </fileset>
-  </path>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "base">
-    <ant dir        = "../base"
-         target     = "compile"
-         inheritAll = "false"/>
-  </target>
-
-  <target name = "compile" depends = "out,base">
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "false"
-           source            = "${target}"
-           target            = "${target}"
-           classpath         = "../base/out:../core/out"
-           srcdir            = "src"
-           destdir           = "out"
-           includes          = "proguard/gradle/ProGuardTask.java">
-      <compilerarg value = "-Xlint:none"/>
-      <classpath refid="gradle.path"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "**/*.properties"/>
-        <include name = "**/*.png"/>
-        <include name = "**/*.gif"/>
-        <include name = "**/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile = "../lib/proguard.jar"
-         update  = "true"
-         basedir = "out"/>
-  </target>
-
-</project>
diff --git a/gui/build.xml b/gui/build.xml
deleted file mode 100644
index 10f1f31d..00000000
--- a/gui/build.xml
+++ /dev/null
@@ -1,65 +0,0 @@
-<!-- Ant build script for the ProGuard GUI. -->
-
-<project name    = "gui"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "base">
-    <ant dir        = "../base"
-         target     = "compile"
-         inheritAll = "false"/>
-  </target>
-
-  <target name = "retrace">
-    <ant dir        = "../retrace"
-         target     = "compile"
-         inheritAll = "false"/>
-  </target>
-
-  <target name = "compile" depends = "out,base,retrace">
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "false"
-           source            = "${target}"
-           target            = "${target}"
-           classpath         = "../base/out:../core/out:../retrace/out"
-           srcdir            = "src"
-           destdir           = "out"
-           includes          = "proguard/gui/ProGuardGUI.java">
-      <compilerarg value = "-Xlint:none"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "**/*.properties"/>
-        <include name = "**/*.png"/>
-        <include name = "**/*.gif"/>
-        <include name = "**/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile  = "../lib/proguardgui.jar"
-         manifest = "src/META-INF/MANIFEST.MF"
-         basedir  = "out"/>
-  </target>
-
-</project>
diff --git a/gui/makefile b/gui/makefile
deleted file mode 100644
index 357386df..00000000
--- a/gui/makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-# GNU/Linux makefile for the ProGuard GUI.
-
-MAIN_CLASS       = proguard/gui/ProGuardGUI
-CLASSPATH        = ../base/$(OUT):../core/$(OUT):../retrace/$(OUT)
-TARGET           = proguardgui
-INCLUDE_MANIFEST = true
-
-include ../buildscripts/functions.mk
diff --git a/retrace/build.xml b/retrace/build.xml
deleted file mode 100644
index 1ff68ffe..00000000
--- a/retrace/build.xml
+++ /dev/null
@@ -1,59 +0,0 @@
-<!-- Ant build script for ReTrace. -->
-
-<project name    = "retrace"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "base">
-    <ant dir        = "../base"
-         target     = "compile"
-         inheritAll = "false"/>
-  </target>
-
-  <target name = "compile" depends = "out,base">
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "false"
-           source            = "${target}"
-           target            = "${target}"
-           classpath         = "../base/out:../core/out"
-           srcdir            = "src"
-           destdir           = "out"
-           includes          = "proguard/retrace/ReTrace.java">
-      <compilerarg value = "-Xlint:none"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "**/*.properties"/>
-        <include name = "**/*.png"/>
-        <include name = "**/*.gif"/>
-        <include name = "**/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile  = "../lib/retrace.jar"
-         manifest = "src/META-INF/MANIFEST.MF"
-         basedir  = "out"/>
-  </target>
-
-</project>
diff --git a/retrace/makefile b/retrace/makefile
deleted file mode 100644
index 4f397bcb..00000000
--- a/retrace/makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-# GNU/Linux makefile for ReTrace.
-
-MAIN_CLASS       = proguard/retrace/ReTrace
-CLASSPATH        = ../base/$(OUT):../core/$(OUT)
-TARGET           = retrace
-INCLUDE_MANIFEST = true
-
-include ../buildscripts/functions.mk
diff --git a/wtk/ant.properties b/wtk/ant.properties
deleted file mode 100644
index 8c7d6fb6..00000000
--- a/wtk/ant.properties
+++ /dev/null
@@ -1,3 +0,0 @@
-# Ant build properties for the ProGuard Wireless Toolkit plugin.
-
-wtk.home = /usr/local/java/wtk
diff --git a/wtk/build.xml b/wtk/build.xml
deleted file mode 100644
index 61a9c0f3..00000000
--- a/wtk/build.xml
+++ /dev/null
@@ -1,69 +0,0 @@
-<!-- Ant build script for the ProGuard Wireless Toolkit plugin. -->
-
-<project name    = "wtk"
-         default = "dist">
-
-  <property file = "../buildscripts/ant.properties"/>
-  <property file = "ant.properties"/>
-  <property name = "wtk.jar" value = "${wtk.home}/wtklib/kenv.zip"/>
-
-  <target name = "clean">
-    <delete quiet = "true">
-      <fileset dir = "out"/>
-    </delete>
-  </target>
-
-  <target name = "out">
-    <mkdir dir = "out"/>
-  </target>
-
-  <target name = "base">
-    <ant dir        = "../base"
-         target     = "compile"
-         inheritAll = "false"/>
-  </target>
-
-  <target name = "compile" depends = "out,base">
-    <fail message="Please set the value of the property wtk.home in the file build.properties.">
-      <condition>
-        <not>
-          <available file="${wtk.jar}"/>
-        </not>
-      </condition>
-    </fail>
-
-    <javac nowarn            = "true"
-           deprecation       = "false"
-           includeantruntime = "false"
-           source            = "${target}"
-           target            = "${target}"
-           classpath         = "../base/out:../core/out:${wtk.jar}"
-           srcdir            = "src"
-           destdir           = "out"
-           includes          = "proguard/wtk/ProGuardObfuscator.java">
-      <compilerarg value = "-Xlint:none"/>
-    </javac>
-  </target>
-
-  <target name = "resources" depends = "out">
-    <copy todir = "out">
-      <fileset dir = "src">
-        <include name = "**/*.properties"/>
-        <include name = "**/*.png"/>
-        <include name = "**/*.gif"/>
-        <include name = "**/*.pro"/>
-      </fileset>
-    </copy>
-  </target>
-
-  <target name = "lib">
-    <mkdir dir = "../lib"/>
-  </target>
-
-  <target name = "dist" depends = "compile,resources,lib">
-    <jar jarfile = "../lib/proguard.jar"
-         update  = "true"
-         basedir = "out"/>
-  </target>
-
-</project>
diff --git a/wtk/makefile b/wtk/makefile
deleted file mode 100644
index 7d0aefe4..00000000
--- a/wtk/makefile
+++ /dev/null
@@ -1,15 +0,0 @@
-# GNU/Linux makefile for the ProGuard Wireless Toolkit plugin.
-
-ifndef WTK_HOME
-WTK_HOME = /usr/local/java/wtk
-endif
-
-MAIN_CLASS = proguard/wtk/ProGuardObfuscator
-WTK_JAR    = $(WTK_HOME)/wtklib/kenv.zip
-CLASSPATH  = ../base/$(OUT):../core/$(OUT):$(WTK_JAR)
-TARGET     = proguard
-UPDATE_JAR = true
-
-include ../buildscripts/functions.mk
-
-$(WTK_JAR): ; $(error Please make sure WTK_HOME is set correctly)