diff --git a/ast/util.go b/ast/util.go
index 978c0fe..45e9945 100644
--- a/ast/util.go
+++ b/ast/util.go
@@ -29,7 +29,7 @@ func (i IdentifierSet) AddIdentifiers(idents Identifiers) {
 
 // ToOrderedSlice returns the elements of the current set as an ordered slice.
 func (i IdentifierSet) ToOrderedSlice() []Identifier {
-	s := make([]Identifier, len(i), len(i))
+	s := make([]Identifier, len(i))
 	j := 0
 	for v := range i {
 		s[j] = v
diff --git a/cmd/internal/cmd/utils.go b/cmd/internal/cmd/utils.go
index 0f66907..15b08cf 100644
--- a/cmd/internal/cmd/utils.go
+++ b/cmd/internal/cmd/utils.go
@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package cmd provides utilities for parsing and handling command line
+// arguments.
 package cmd
 
 import (
diff --git a/internal/errors/static_error.go b/internal/errors/static_error.go
index fdb8f0c..535da5e 100644
--- a/internal/errors/static_error.go
+++ b/internal/errors/static_error.go
@@ -14,6 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package errors provides internal representation of errors.
 package errors
 
 import (
diff --git a/internal/formatter/jsonnetfmt.go b/internal/formatter/jsonnetfmt.go
index 3eeaed5..5007921 100644
--- a/internal/formatter/jsonnetfmt.go
+++ b/internal/formatter/jsonnetfmt.go
@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package formatter provides API for producing pretty-printed source
+// from AST.
 package formatter
 
 import (
diff --git a/internal/pass/pass.go b/internal/pass/pass.go
index 2c6b5df..b3475fe 100644
--- a/internal/pass/pass.go
+++ b/internal/pass/pass.go
@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package pass provides a visitor framework for source code analysis
+// and transformation.
 package pass
 
 import (
diff --git a/internal/program/program.go b/internal/program/program.go
index 32014d3..c135024 100644
--- a/internal/program/program.go
+++ b/internal/program/program.go
@@ -1,3 +1,4 @@
+// Package program provides API for AST pre-processing (desugaring, static analysis).
 package program
 
 import (
diff --git a/internal/testutils/test_utils.go b/internal/testutils/test_utils.go
index ad215b7..af67294 100644
--- a/internal/testutils/test_utils.go
+++ b/internal/testutils/test_utils.go
@@ -1,3 +1,4 @@
+// Package testutils provides general testing utilities.
 package testutils
 
 import (
diff --git a/linter/internal/common/common.go b/linter/internal/common/common.go
index 6156703..d41b8c9 100644
--- a/linter/internal/common/common.go
+++ b/linter/internal/common/common.go
@@ -1,7 +1,10 @@
+// Package common provides utilities to be used in multiple linter
+// subpackages.
 package common
 
 import (
 	"github.com/google/go-jsonnet/ast"
+	"github.com/google/go-jsonnet/internal/errors"
 )
 
 // VariableKind allows distinguishing various kinds of variables.
@@ -33,3 +36,19 @@ type VariableInfo struct {
 	// More precisely it maps every *ast.Var to the variable.
 	VarAt map[ast.Node]*Variable
 }
+
+// ErrCollector is a struct for accumulating warnings / errors from the linter.
+// It is slightly more convenient and more clear than passing pointers to slices around.
+type ErrCollector struct {
+	Errs []errors.StaticError
+}
+
+// Collect adds an error to the list
+func (ec *ErrCollector) Collect(err errors.StaticError) {
+	ec.Errs = append(ec.Errs, err)
+}
+
+// StaticErr constructs a static error from msg and loc and adds it to the list.
+func (ec *ErrCollector) StaticErr(msg string, loc *ast.LocationRange) {
+	ec.Collect(errors.MakeStaticError(msg, *loc))
+}
diff --git a/linter/internal/traversal/traversal.go b/linter/internal/traversal/traversal.go
index d33e6c4..c57ffe9 100644
--- a/linter/internal/traversal/traversal.go
+++ b/linter/internal/traversal/traversal.go
@@ -1,19 +1,18 @@
-package traversal
-
 // Package traversal provides relatively lightweight checks
 // which can all fit within one traversal of the AST.
 // Currently available checks:
 // * Loop detection
 // TODO(sbarzowski) add more
+package traversal
 
 import (
 	"github.com/google/go-jsonnet/ast"
-	"github.com/google/go-jsonnet/linter/internal/utils"
+	"github.com/google/go-jsonnet/linter/internal/common"
 
 	"github.com/google/go-jsonnet/internal/parser"
 )
 
-func findLoopingInChildren(node ast.Node, vars map[ast.Identifier]ast.Node, runOf map[ast.Identifier]int, currentRun int, ec *utils.ErrCollector) bool {
+func findLoopingInChildren(node ast.Node, vars map[ast.Identifier]ast.Node, runOf map[ast.Identifier]int, currentRun int, ec *common.ErrCollector) bool {
 	for _, c := range parser.DirectChildren(node) {
 		found := findLooping(c, vars, runOf, currentRun, ec)
 		if found {
@@ -23,7 +22,7 @@ func findLoopingInChildren(node ast.Node, vars map[ast.Identifier]ast.Node, runO
 	return false
 }
 
-func findLooping(node ast.Node, vars map[ast.Identifier]ast.Node, runOf map[ast.Identifier]int, currentRun int, ec *utils.ErrCollector) bool {
+func findLooping(node ast.Node, vars map[ast.Identifier]ast.Node, runOf map[ast.Identifier]int, currentRun int, ec *common.ErrCollector) bool {
 	switch node := node.(type) {
 	case *ast.Var:
 		_, varFromThisLocal := vars[node.Id]
@@ -43,7 +42,7 @@ func findLooping(node ast.Node, vars map[ast.Identifier]ast.Node, runOf map[ast.
 	return findLoopingInChildren(node, vars, runOf, currentRun, ec)
 }
 
-func findLoopingInLocal(node *ast.Local, ec *utils.ErrCollector) {
+func findLoopingInLocal(node *ast.Local, ec *common.ErrCollector) {
 	vars := make(map[ast.Identifier]ast.Node)
 	runOf := make(map[ast.Identifier]int)
 	for _, b := range node.Binds {
@@ -62,7 +61,7 @@ func findLoopingInLocal(node *ast.Local, ec *utils.ErrCollector) {
 
 // Traverse visits all nodes in the AST and runs appropriate
 // checks.
-func Traverse(node ast.Node, ec *utils.ErrCollector) {
+func Traverse(node ast.Node, ec *common.ErrCollector) {
 	switch node := node.(type) {
 	case *ast.Local:
 		findLoopingInLocal(node, ec)
diff --git a/linter/internal/types/check.go b/linter/internal/types/check.go
index bbb3316..0c1276a 100644
--- a/linter/internal/types/check.go
+++ b/linter/internal/types/check.go
@@ -6,10 +6,9 @@ import (
 	"github.com/google/go-jsonnet/ast"
 	"github.com/google/go-jsonnet/internal/parser"
 	"github.com/google/go-jsonnet/linter/internal/common"
-	"github.com/google/go-jsonnet/linter/internal/utils"
 )
 
-func checkSubexpr(node ast.Node, typeOf exprTypes, ec *utils.ErrCollector) {
+func checkSubexpr(node ast.Node, typeOf exprTypes, ec *common.ErrCollector) {
 	for _, child := range parser.Children(node) {
 		check(child, typeOf, ec)
 	}
@@ -17,7 +16,7 @@ func checkSubexpr(node ast.Node, typeOf exprTypes, ec *utils.ErrCollector) {
 
 // check verifies that the types are valid for a given program, given
 // the previously resolved types.
-func check(node ast.Node, typeOf exprTypes, ec *utils.ErrCollector) {
+func check(node ast.Node, typeOf exprTypes, ec *common.ErrCollector) {
 	checkSubexpr(node, typeOf, ec)
 	switch node := node.(type) {
 	case *ast.Apply:
@@ -89,7 +88,7 @@ func check(node ast.Node, typeOf exprTypes, ec *utils.ErrCollector) {
 }
 
 // TODO(sbarzowski) eliminate duplication with the interpreter maybe (this is AST-level and there it's value-level)
-func checkArgs(params []ast.Parameter, args *ast.Arguments, loc *ast.LocationRange, ec *utils.ErrCollector) {
+func checkArgs(params []ast.Parameter, args *ast.Arguments, loc *ast.LocationRange, ec *common.ErrCollector) {
 	received := make(map[ast.Identifier]bool)
 	accepted := make(map[ast.Identifier]bool)
 
@@ -133,7 +132,7 @@ func checkArgs(params []ast.Parameter, args *ast.Arguments, loc *ast.LocationRan
 // * root nodes of all (transitively) imported Jsonnet files
 // * resolution of variables in all files
 // * importFunc which allows resolving imports
-func Check(mainNode ast.Node, roots map[string]ast.Node, vars map[string]map[ast.Node]*common.Variable, importFunc ImportFunc, ec *utils.ErrCollector) {
+func Check(mainNode ast.Node, roots map[string]ast.Node, vars map[string]map[ast.Node]*common.Variable, importFunc ImportFunc, ec *common.ErrCollector) {
 	et := make(exprTypes)
 	g := newTypeGraph(importFunc)
 	g.addRoots(roots, vars)
diff --git a/linter/internal/types/doc.go b/linter/internal/types/doc.go
index ab831f2..bafb1ed 100644
--- a/linter/internal/types/doc.go
+++ b/linter/internal/types/doc.go
@@ -1,5 +1,5 @@
-package types
-
+// Package types provides type inference functionality. 
+//
 // Even though Jsonnet doesn't have a concept of static types
 // we can infer for each expression what values it can take.
 // Of course we cannot do this accurately at all times, but even
@@ -17,3 +17,5 @@ package types
 // First of all type processing split into two very distinct phases:
 // 1) Finding a type - an upper bound for the set of possible values for each expression.
 // 2) Checking all expressions in the AST using this information.
+package types
+
diff --git a/linter/internal/utils/BUILD.bazel b/linter/internal/utils/BUILD.bazel
deleted file mode 100644
index 3caa518..0000000
--- a/linter/internal/utils/BUILD.bazel
+++ /dev/null
@@ -1,12 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
-
-go_library(
-    name = "go_default_library",
-    srcs = ["utils.go"],
-    importpath = "github.com/google/go-jsonnet/linter/internal/utils",
-    visibility = ["//linter:__subpackages__"],
-    deps = [
-        "//ast:go_default_library",
-        "//internal/errors:go_default_library",
-    ],
-)
diff --git a/linter/internal/utils/utils.go b/linter/internal/utils/utils.go
deleted file mode 100644
index 4074e2a..0000000
--- a/linter/internal/utils/utils.go
+++ /dev/null
@@ -1,22 +0,0 @@
-package utils
-
-import (
-	"github.com/google/go-jsonnet/ast"
-	"github.com/google/go-jsonnet/internal/errors"
-)
-
-// ErrCollector is a struct for accumulating warnings / errors from the linter.
-// It is slightly more convenient and more clear than passing pointers to slices around.
-type ErrCollector struct {
-	Errs []errors.StaticError
-}
-
-// Collect adds an error to the list
-func (ec *ErrCollector) Collect(err errors.StaticError) {
-	ec.Errs = append(ec.Errs, err)
-}
-
-// StaticErr constructs a static error from msg and loc and adds it to the list.
-func (ec *ErrCollector) StaticErr(msg string, loc *ast.LocationRange) {
-	ec.Collect(errors.MakeStaticError(msg, *loc))
-}
diff --git a/linter/internal/variables/find_variables.go b/linter/internal/variables/find_variables.go
index baae023..cfdef8e 100644
--- a/linter/internal/variables/find_variables.go
+++ b/linter/internal/variables/find_variables.go
@@ -1,3 +1,5 @@
+// Package variables allows collecting the information about how variables
+// are used.
 package variables
 
 import (
diff --git a/linter/linter.go b/linter/linter.go
index 7063e21..7154dfa 100644
--- a/linter/linter.go
+++ b/linter/linter.go
@@ -12,7 +12,6 @@ import (
 	"github.com/google/go-jsonnet/linter/internal/common"
 	"github.com/google/go-jsonnet/linter/internal/traversal"
 	"github.com/google/go-jsonnet/linter/internal/types"
-	"github.com/google/go-jsonnet/linter/internal/utils"
 	"github.com/google/go-jsonnet/linter/internal/variables"
 )
 
@@ -66,7 +65,7 @@ func lint(vm *jsonnet.VM, node nodeWithLocation, errWriter *ErrorWriter) {
 			errWriter.writeError(vm, errors.MakeStaticError("Unused variable: "+string(v.Name), v.LocRange))
 		}
 	}
-	ec := utils.ErrCollector{}
+	ec := common.ErrCollector{}
 
 	vars := make(map[string]map[ast.Node]*common.Variable)
 	for importedPath, info := range variablesInFile {