diff --git a/Makefile b/Makefile
index d94c960..bdf75e1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,32 @@
+# customizable output dir
 DEST_DIR ?= dist
+
+# find all issues and determine required output files
 ISSUES != find . -path "./issues/*" -type d
 DEST_PDF_FILES := $(ISSUES:./issues/%=$(DEST_DIR)/issue-%.pdf)
 DEST_HTML_FILES := $(ISSUES:./issues/%=$(DEST_DIR)/issue-%.html)
 DEST_EPUB_FILES := $(ISSUES:./issues/%=$(DEST_DIR)/issue-%.epub)
 
+# deps
 PANDOC != command -v pandoc 2> /dev/null
+XELATEX != command -v xelatex 2> /dev/null
 
-all: $(DEST_PDF_FILES) $(DEST_HTML_FILES) $(DEST_EPUB_FILES)
+# default target
+help:
+	@echo "Targets:"
+	@echo -e "\tall   - build all formats"
+	@echo -e "\tpdf   - generate all issues as pdf"
+	@echo -e "\thtml  - generate all issues as html"
+	@echo -e "\tepub  - generate all issues as epub"
+	@echo -e "\tclean - remove build artifacts"
+
+all: pdf html epub dep-pandoc
+
+pdf: $(DEST_PDF_FILES) dep-xelatex
+
+html: $(DEST_HTML_FILES)
+
+epub: $(DEST_EPUB_FILES)
 
 $(DEST_DIR)/issue-%.pdf: issues/%
 	@echo "building $@"
@@ -54,7 +74,17 @@ $(DEST_DIR)/issue-%.epub: issues/%
 
 clean:
 	@echo "removing build artifacts"
-	@rm $(DEST_PDF_FILES) $(DEST_HTML_FILES) $(DEST_EPUB_FILES)
+	@rm $(DEST_DIR)/*.{pdf,html,epub}
 
-.PHONY: clean
+dep-pandoc:
+ifndef PANDOC
+	$(error missing dependency 'pandoc'. please install and try again)
+endif
+
+dep-xelatex:
+ifndef XELATEX
+	$(error missing dependency 'xelatex'. please install and try again)
+endif
+
+.PHONY: clean help dep-pandoc dep-xelatex