diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 6fdabaf8583..d003dee9735 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -1,4 +1,4 @@
-'name': 'golangci-lint'
+'name': 'lint'
 'on':
   'push':
     'tags':
@@ -7,16 +7,13 @@
     - '*'
   'pull_request':
 'jobs':
-  'golangci':
+  'go-lint':
     'runs-on': 'ubuntu-latest'
     'steps':
     - 'uses': 'actions/checkout@v2'
-    - 'name': 'golangci-lint'
-      'uses': 'golangci/golangci-lint-action@v2.3.0'
-      'with':
-        # This field is required.  Don't set the patch version to always use
-        # the latest patch version.
-        'version': 'v1.32'
+    - 'name': 'run-lint'
+      'run': >
+        make go-install-tools go-lint
   'eslint':
     'runs-on': 'ubuntu-latest'
     'steps':
@@ -27,7 +24,7 @@
       'run': 'npm --prefix client run lint'
   'notify':
     'needs':
-    - 'golangci'
+    - 'go-lint'
     - 'eslint'
     # Secrets are not passed to workflows that are triggered by a pull request
     # from a fork.
diff --git a/.gitignore b/.gitignore
index 5b067dced96..beba3ce17d0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,31 +1,22 @@
-.DS_Store
-/.vscode
-.idea
-/AdGuardHome
-/AdGuardHome.exe
-/AdGuardHome.yaml
-/AdGuardHome.log
-/data/
+# Please, DO NOT put your text editors' temporary files here.  The more are
+# added, the harder it gets to maintain and manage projects' gitignores.  Put
+# them into your global gitignore file instead.
+#
+# See https://stackoverflow.com/a/7335487/1892060.
+#
+# Only build, run, and test outputs here.  Sorted.
+*-packr.go
+*.db
+*.snap
+/bin/
 /build/
+/data/
 /dist/
-/client/node_modules/
-/querylog.json
-/querylog.json.1
+/dnsfilter/tests/dnsfilter.TestLotsOfRules*.pprof
+/dnsfilter/tests/top-1m.csv
+/launchpad_credentials
+/querylog.json*
+/snapcraft_login
+AdGuardHome*
 coverage.txt
-leases.db
-
-# Test output
-dnsfilter/tests/top-1m.csv
-dnsfilter/tests/dnsfilter.TestLotsOfRules*.pprof
-
-# Snapcraft build temporary files
-*.snap
-launchpad_credentials
-snapcraft_login
-snapcraft.yaml.bak
-
-# IntelliJ IDEA project files
-*.iml
-
-# Packr
-*-packr.go
+node_modules/
diff --git a/HACKING.md b/HACKING.md
index ae987af6756..77c47eab089 100644
--- a/HACKING.md
+++ b/HACKING.md
@@ -1,9 +1,9 @@
  #  *AdGuardHome* Developer Guidelines
 
-As of **2020-11-27**, this document is a work-in-progress, but should still be
-followed.  Some of the rules aren't enforced as thoroughly or remain broken in
-old code, but this is still the place to find out about what we **want** our
-code to look like.
+As of **December 2020**, this document is partially a work-in-progress, but
+should still be followed.  Some of the rules aren't enforced as thoroughly or
+remain broken in old code, but this is still the place to find out about what we
+**want** our code to look like.
 
 The rules are mostly sorted in the alphabetical order.
 
@@ -32,6 +32,11 @@ The rules are mostly sorted in the alphabetical order.
 
 ##  *Go*
 
+> Not Golang, not GO, not GOLANG, not GoLang. It is Go in natural language,
+> golang for others.
+
+— [@rakyll](https://twitter.com/rakyll/status/1229850223184269312)
+
  ###  Code And Naming
 
  *  Avoid `goto`.
@@ -141,6 +146,19 @@ The rules are mostly sorted in the alphabetical order.
 
  *  **TODO(a.garipov):** Define our *Markdown* conventions.
 
+##  Shell Scripting
+
+ *  Avoid bashisms, prefer *POSIX* features only.
+
+ *  Prefer `'raw strings'` to `"double quoted strings"` whenever possible.
+
+ *  Put spaces within `$( cmd )`, `$(( expr ))`, and `{ cmd; }`.
+
+ *  Use `set -e -f -u` and also `set -x` in verbose mode.
+
+ *  Use the `"$var"` form instead of the `$var` form, unless word splitting is
+    required.
+
 ##  Text, Including Comments
 
  *  End sentences with appropriate punctuation.
diff --git a/Makefile b/Makefile
index f98d430f61d..476702004a3 100644
--- a/Makefile
+++ b/Makefile
@@ -26,7 +26,8 @@
 #     * DOCKER_IMAGE_NAME - adguard/adguard-home
 #     * DOCKER_OUTPUT - type=image,name=adguard/adguard-home,push=true
 
-GOPATH := $(shell go env GOPATH)
+GO := go
+GOPATH := $(shell $(GO) env GOPATH)
 PWD := $(shell pwd)
 TARGET=AdGuardHome
 BASE_URL="https://static.adguard.com/adguardhome/$(CHANNEL)"
@@ -122,9 +123,9 @@ init:
 	git config core.hooksPath .githooks
 
 build: client_with_deps
-	go mod download
-	PATH=$(GOPATH)/bin:$(PATH) go generate ./...
-	CGO_ENABLED=0 go build -ldflags="-s -w -X main.version=$(VERSION) -X main.channel=$(CHANNEL) -X main.goarm=$(GOARM)"
+	$(GO) mod download
+	PATH=$(GOPATH)/bin:$(PATH) $(GO) generate ./...
+	CGO_ENABLED=0 $(GO) build -ldflags="-s -w -X main.version=$(VERSION) -X main.channel=$(CHANNEL) -X main.goarm=$(GOARM)"
 	PATH=$(GOPATH)/bin:$(PATH) packr clean
 
 client:
@@ -151,38 +152,40 @@ docker:
 	@echo Now you can run the docker image:
 	@echo docker run --name "adguard-home" -p 53:53/tcp -p 53:53/udp -p 80:80/tcp -p 443:443/tcp -p 853:853/tcp -p 3000:3000/tcp $(DOCKER_IMAGE_NAME)
 
-lint: lint-js lint-go
+lint: js-lint go-lint
 
-lint-js: dependencies
-	@echo Running js linter
+js-lint: dependencies
 	npm --prefix client run lint
 
-lint-go:
-	@echo Running go linter
-	golangci-lint run
+go-install-tools:
+	env GO=$(GO) sh ./scripts/go-install-tools.sh
+
+go-lint:
+	env GO=$(GO) PATH="$$PWD/bin:$$PATH" sh ./scripts/go-lint.sh
 
 test: test-js test-go
 
-test-js:
+js-test:
 	npm run test --prefix client
 
-test-go:
-	go test $(TEST_FLAGS) --coverprofile coverage.txt ./...
+go-test:
+	$(GO) test $(TEST_FLAGS) --coverprofile coverage.txt ./...
 
 ci: client_with_deps
-	go mod download
+	$(GO) mod download
 	$(MAKE) test
 
 dependencies:
 	npm --prefix client ci
-	go mod download
+	$(GO) mod download
 
 clean:
 	rm -f ./AdGuardHome ./AdGuardHome.exe ./coverage.txt
-	rm -f -r ./build/ ./client/node_modules/ ./data/ $(DIST_DIR)
+	rm -f -r ./build/ ./client/node_modules/ ./data/ ./$(DIST_DIR)/
 # Set the GOPATH explicitly in case make clean is called from under sudo
 # after a Docker build.
 	env PATH="$(GOPATH)/bin:$$PATH" packr clean
+	rm -f -r ./bin/
 
 docker-multi-arch:
 	DOCKER_CLI_EXPERIMENTAL=enabled \
@@ -200,7 +203,7 @@ docker-multi-arch:
 	@echo docker run --name "adguard-home" -p 53:53/tcp -p 53:53/udp -p 80:80/tcp -p 443:443/tcp -p 853:853/tcp -p 3000:3000/tcp $(DOCKER_IMAGE_NAME)
 
 release: client_with_deps
-	go mod download
+	$(GO) mod download
 	@echo Starting release build: version $(VERSION), channel $(CHANNEL)
 	CHANNEL=$(CHANNEL) $(GORELEASER_COMMAND)
 	$(call write_version_file,$(VERSION))
diff --git a/README.md b/README.md
index 5d774ee4090..b38452d7abe 100644
--- a/README.md
+++ b/README.md
@@ -171,9 +171,6 @@ You will need this to build AdGuard Home:
  * [node.js](https://nodejs.org/en/download/) v10.16.2 or later.
  * [npm](https://www.npmjs.com/) v6.14 or later.
 
-Optionally, for Go devs:
- * [golangci-lint](https://github.com/golangci/golangci-lint)
- 
 ### Building
 
 Open Terminal and execute these commands:
@@ -186,7 +183,7 @@ make
 
 Check the [`Makefile`](https://github.com/AdguardTeam/AdGuardHome/blob/master/Makefile) to learn about other commands.
 
-**Building for a different platform.** You can build AdGuard for any OS/ARCH just like any other Golang project.
+**Building for a different platform.** You can build AdGuard for any OS/ARCH just like any other Go project.
 In order to do this, specify `GOOS` and `GOARCH` env variables before running make.
 
 For example:
@@ -331,4 +328,4 @@ For a full list of all node.js packages in use, please take a look at [client/pa
 <a id="privacy"></a>
 ## Privacy
 
-Our main idea is that you are the one, who should be in control of your data. So it is only natural, that AdGuard Home does not collect any usage statistics, and does not use any web services unless you configure it to do so. Full policy with every bit that _could in theory be_ sent by AdGuard Home is available [here](https://adguard.com/en/privacy/home.html).
\ No newline at end of file
+Our main idea is that you are the one, who should be in control of your data. So it is only natural, that AdGuard Home does not collect any usage statistics, and does not use any web services unless you configure it to do so. Full policy with every bit that _could in theory be_ sent by AdGuard Home is available [here](https://adguard.com/en/privacy/home.html).
diff --git a/internal/tools/go.mod b/internal/tools/go.mod
new file mode 100644
index 00000000000..73bb637bb3f
--- /dev/null
+++ b/internal/tools/go.mod
@@ -0,0 +1,24 @@
+module github.com/AdguardTeam/AdGuardHome/internal/tools
+
+go 1.15
+
+require (
+	dmitri.shuralyov.com/go/generated v0.0.0-20170818220700-b1254a446363 // indirect
+	github.com/client9/misspell v0.3.4 // indirect
+	github.com/fzipp/gocyclo v0.3.1
+	github.com/golangci/misspell v0.3.5
+	github.com/google/go-cmp v0.5.4 // indirect
+	github.com/gookit/color v1.3.3 // indirect
+	github.com/gordonklaus/ineffassign v0.0.0-20201107091007-3b93a8888063
+	github.com/kisielk/errcheck v1.4.0
+	github.com/kyoh86/looppointer v0.1.7
+	github.com/kyoh86/nolint v0.0.1 // indirect
+	github.com/securego/gosec/v2 v2.5.0
+	golang.org/x/lint v0.0.0-20200302205851-738671d3881b
+	golang.org/x/mod v0.4.0 // indirect
+	golang.org/x/tools v0.0.0-20201208062317-e652b2f42cc7
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+	honnef.co/go/tools v0.0.1-2020.1.6
+	mvdan.cc/gofumpt v0.0.0-20201129102820-5c11c50e9475
+	mvdan.cc/unparam v0.0.0-20200501210554-b37ab49443f7
+)
diff --git a/internal/tools/go.sum b/internal/tools/go.sum
new file mode 100644
index 00000000000..968ac8a4e02
--- /dev/null
+++ b/internal/tools/go.sum
@@ -0,0 +1,164 @@
+dmitri.shuralyov.com/go/generated v0.0.0-20170818220700-b1254a446363 h1:o4lAkfETerCnr1kF9/qwkwjICnU+YLHNDCM8h2xj7as=
+dmitri.shuralyov.com/go/generated v0.0.0-20170818220700-b1254a446363/go.mod h1:WG7q7swWsS2f9PYpt5DoEP/EBYWx8We5UoRltn9vJl8=
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/client9/misspell v0.3.4 h1:ta993UF76GwbvJcIo3Y68y/M3WxlpEHPWIGDkJYwzJI=
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+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
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diff --git a/internal/tools/tools.go b/internal/tools/tools.go
new file mode 100644
index 00000000000..b2f83783a7d
--- /dev/null
+++ b/internal/tools/tools.go
@@ -0,0 +1,22 @@
+// +build tools
+
+// Package tools and its main module are a nested internal module containing our
+// development tool dependencies.
+//
+// See https://github.com/golang/go/wiki/Modules#how-can-i-track-tool-dependencies-for-a-module.
+package tools
+
+import (
+	_ "github.com/fzipp/gocyclo/cmd/gocyclo"
+	_ "github.com/golangci/misspell/cmd/misspell"
+	_ "github.com/gordonklaus/ineffassign"
+	_ "github.com/kisielk/errcheck"
+	_ "github.com/kyoh86/looppointer"
+	_ "github.com/securego/gosec/v2/cmd/gosec"
+	_ "golang.org/x/lint/golint"
+	_ "golang.org/x/tools/go/analysis/passes/nilness/cmd/nilness"
+	_ "golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow"
+	_ "honnef.co/go/tools/cmd/staticcheck"
+	_ "mvdan.cc/gofumpt/gofumports"
+	_ "mvdan.cc/unparam"
+)
diff --git a/scripts/go-install-tools.sh b/scripts/go-install-tools.sh
new file mode 100644
index 00000000000..e75a54e4256
--- /dev/null
+++ b/scripts/go-install-tools.sh
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+test "$VERBOSE" = '1' && set -x
+set -e -f -u
+
+# TODO(a.garipov): Add goconst?
+
+env GOBIN="${PWD}/bin" "$GO" install --modfile=./internal/tools/go.mod\
+	github.com/fzipp/gocyclo/cmd/gocyclo\
+	github.com/golangci/misspell/cmd/misspell\
+	github.com/gordonklaus/ineffassign\
+	github.com/kisielk/errcheck\
+	github.com/kyoh86/looppointer/cmd/looppointer\
+	github.com/securego/gosec/v2/cmd/gosec\
+	golang.org/x/lint/golint\
+	golang.org/x/tools/go/analysis/passes/nilness/cmd/nilness\
+	golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow\
+	honnef.co/go/tools/cmd/staticcheck\
+	mvdan.cc/gofumpt\
+	mvdan.cc/unparam\
+	;
diff --git a/scripts/go-lint.sh b/scripts/go-lint.sh
new file mode 100644
index 00000000000..9f4502c6357
--- /dev/null
+++ b/scripts/go-lint.sh
@@ -0,0 +1,95 @@
+#!/bin/sh
+
+# Verbosity levels:
+#   0 = Don't print anything except for errors.
+#   1 = Print commands, but not nested commands.
+#   2 = Print everything.
+test "${VERBOSE:=0}" -gt '0' && set -x
+
+# Set $EXITONERROR to zero to see all errors.
+test "${EXITONERROR:=1}" = '0' && set +e || set -e
+
+# We don't need glob expansions and we want to see errors about unset
+# variables.
+set -f -u
+
+# blocklistimports is a simple check against unwanted packages.
+# Currently it only looks for package log which is replaced by our own
+# package github.com/AdguardTeam/golibs/log.
+blocklistimports () {
+	git grep -F -e '"log"' -- '*.go' || exit 0;
+}
+
+# underscores is a simple check against Go filenames with underscores.
+underscores () {
+	git ls-files '*_*.go' | { grep -F -e '_darwin.go' \
+		-e '_freebsd.go' -e '_linux.go' -e '_others.go' \
+		-e '_test.go' -e '_unix.go' -e '_windows.go' \
+		-v || exit 0; }
+}
+
+# exitonoutput exits with a nonzero exit code if there is anything in
+# the command's combined output.
+exitonoutput() {
+	test "$VERBOSE" -lt '2' && set +x
+
+	cmd="$1"
+	shift
+
+	exitcode='0'
+	output="$("$cmd" "$@" 2>&1)"
+	if [ "$output" != '' ]
+	then
+		if [ "$*" != '' ]
+		then
+			echo "combined output of '$cmd $@':"
+		else
+			echo "combined output of '$cmd':"
+		fi
+
+		echo "$output"
+
+		exitcode='1'
+	fi
+
+	test "$VERBOSE" -gt '0' && set -x
+
+	return "$exitcode"
+}
+
+exitonoutput blocklistimports
+
+exitonoutput underscores
+
+exitonoutput gofumpt --extra -l -s .
+
+golint --set_exit_status ./...
+
+"$GO" vet ./...
+
+gocyclo --over 20 .
+
+gosec --quiet .
+
+ineffassign .
+
+unparam ./...
+
+misspell --error ./...
+
+looppointer ./...
+
+nilness ./...
+
+# TODO(a.garipov): Enable shadow after fixing all of the shadowing.
+# shadow --strict ./...
+
+# TODO(a.garipov): Enable errcheck fully after handling all errors,
+# including the deferred ones, properly.  Also, perhaps, enable --blank.
+# errcheck ./...
+exitonoutput sh -c '
+	errcheck --asserts ./... |\
+		{ grep -e "defer" -e "_test\.go:" -v || exit 0; }
+'
+
+staticcheck --checks='all' ./...