diff --git a/Gemfile b/Gemfile
index 2e880cdc6e..cf99c5a414 100644
--- a/Gemfile
+++ b/Gemfile
@@ -35,4 +35,5 @@ group :development do
   # Ruby 3 no longer ships with a web server
   gem 'puma' if RUBY_VERSION >= '3'
   gem 'shotgun'
+  gem 'rackup'
 end
diff --git a/docs/Docker.md b/docs/Docker.md
index 4670b31ed6..02b82efea8 100644
--- a/docs/Docker.md
+++ b/docs/Docker.md
@@ -75,7 +75,7 @@ Pretty sweet. Let's unpack this:
 Just replace the `bundle` command with `rake`:
 
 ```bash
-docker run -t -v $PWD:/app -v /tmp/vendor:/vendor -w /app -e BUNDLE_PATH=/vendor ruby rake
+docker run -t -v $PWD:/app -v /tmp/vendor:/vendor -w /app -e BUNDLE_PATH=/vendor ruby bundle exec rake
 ```
 
 ### Running Rack
diff --git a/lib/rouge/demos/dax b/lib/rouge/demos/dax
new file mode 100644
index 0000000000..67aac9dfa7
--- /dev/null
+++ b/lib/rouge/demos/dax
@@ -0,0 +1,15 @@
+DEFINE MEASURE 'foo'[measure1] = 
+    VAR variable = 4.5
+    RETURN
+    SUMX( VALUES( 'bar'[col] ), 'bar'[col] + variable ) 
+
+EVALUATE
+    ADDCOLUMNS(
+        VALUES( 'Date'[Year Month] )
+        ,"@sumBar"
+        ,CALCULATE(
+            [measure1]
+            ,REMOVEFILTERS()
+            ,USERELATIONSHIP( 'Date'[Date], 'bar'[Order Date] )
+        )
+    )
diff --git a/lib/rouge/lexers/dax.rb b/lib/rouge/lexers/dax.rb
new file mode 100644
index 0000000000..010c36a283
--- /dev/null
+++ b/lib/rouge/lexers/dax.rb
@@ -0,0 +1,143 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+module Rouge
+  module Lexers
+    class DAX < RegexLexer
+      title "DAX"
+      desc "Data Analysis Expressions (DAX) https://learn.microsoft.com/en-us/dax/."
+      tag 'dax'
+      filenames '*.dax'
+      mimetypes 
+
+      def self.functions
+        # sources:
+        # https://learn.microsoft.com/en-us/dax/
+        # https://learn.microsoft.com/en-us/dax/dax-function-reference
+        @functions ||= Set.new %w(
+          ABS ACCRINT ACCRINTM ACOS ACOSH ACOT ACOTH ADDCOLUMNS ADDMISSINGITEMS
+          ALL ALLCROSSFILTERED ALLEXCEPT ALLNOBLANKROW ALLSELECTED AMORDEGRC
+          AMORLINC AND APPROXIMATEDISTINCTCOUNT ASIN ASINH ATAN ATANH AVERAGE
+          AVERAGEA AVERAGEX BETA.DIST BETA.INV BITAND BITLSHIFT BITOR BITRSHIFT
+          BITXOR BLANK CALCULATE CALCULATETABLE CALENDAR CALENDARAUTO CEILING
+          CHISQ.DIST CHISQ.DIST.RT CHISQ.INV CHISQ.INV.RT CLOSINGBALANCEMONTH
+          CLOSINGBALANCEQUARTER CLOSINGBALANCEYEAR COALESCE COLLAPSE COLLAPSEALL
+          COLUMNSTATISTICS COMBIN COMBINA COMBINEVALUES CONCATENATE CONCATENATEX
+          CONFIDENCE.NORM CONFIDENCE.T CONTAINS CONTAINSROW CONTAINSSTRING
+          CONTAINSSTRINGEXACT CONVERT COS COSH COT COTH COUNT COUNTA COUNTAX
+          COUNTBLANK COUNTROWS COUNTX COUPDAYBS COUPDAYS COUPDAYSNC COUPNCD
+          COUPNUM COUPPCD CROSSFILTER CROSSJOIN CUMIPMT CUMPRINC CURRENCY
+          CURRENTGROUP CUSTOMDATA DATATABLE DATE DATEADD DATEDIFF DATESBETWEEN
+          DATESINPERIOD DATESMTD DATESQTD DATESYTD DATEVALUE DAY DB DDB DEGREES
+          DETAILROWS DISC DISTINCT DISTINCTCOUNT DISTINCTCOUNTNOBLANK DIVIDE
+          DOLLARDE DOLLARFR DURATION EARLIER EARLIEST EDATE EFFECT ENDOFMONTH
+          ENDOFQUARTER ENDOFYEAR EOMONTH ERROR EVALUATEANDLOG EVEN EXACT EXCEPT
+          EXP EXPAND EXPANDALL EXPON.DIST EXTERNALMEASURE FACT FALSE FILTER
+          FILTERS FIND FIRST FIRSTDATE FIRSTNONBLANK FIRSTNONBLANKVALUE FIXED
+          FLOOR FORMAT FV GCD GENERATE GENERATEALL GENERATESERIES GEOMEAN
+          GEOMEANX GROUPBY HASH HASONEFILTER HASONEVALUE HOUR IF IF.EAGER IFERROR
+          IGNORE INDEX INFO.ALTERNATEOFDEFINITIONS INFO.ANNOTATIONS
+          INFO.ATTRIBUTEHIERARCHIES INFO.ATTRIBUTEHIERARCHYSTORAGES
+          INFO.CALCULATIONGROUPS INFO.CALCULATIONITEMS INFO.CHANGEDPROPERTIES
+          INFO.COLUMNPARTITIONSTORAGES INFO.COLUMNPERMISSIONS INFO.COLUMNS
+          INFO.COLUMNSTORAGES INFO.CULTURES INFO.DATACOVERAGEDEFINITIONS
+          INFO.DATASOURCES INFO.DELTATABLEMETADATASTORAGES
+          INFO.DETAILROWSDEFINITIONS INFO.DICTIONARYSTORAGES
+          INFO.EXCLUDEDARTIFACTS INFO.EXPRESSIONS INFO.EXTENDEDPROPERTIES
+          INFO.FORMATSTRINGDEFINITIONS INFO.FUNCTIONS
+          INFO.GENERALSEGMENTMAPSEGMENTMETADATASTORAGES INFO.GROUPBYCOLUMNS
+          INFO.HIERARCHIES INFO.HIERARCHYSTORAGES INFO.KPIS INFO.LEVELS
+          INFO.LINGUISTICMETADATA INFO.MEASURES INFO.MODEL
+          INFO.OBJECTTRANSLATIONS INFO.PARQUETFILESTORAGES INFO.PARTITIONS
+          INFO.PARTITIONSTORAGES INFO.PERSPECTIVECOLUMNS
+          INFO.PERSPECTIVEHIERARCHIES INFO.PERSPECTIVEMEASURES INFO.PERSPECTIVES
+          INFO.PERSPECTIVETABLES INFO.QUERYGROUPS INFO.REFRESHPOLICIES
+          INFO.RELATEDCOLUMNDETAILS INFO.RELATIONSHIPINDEXSTORAGES
+          INFO.RELATIONSHIPS INFO.RELATIONSHIPSTORAGES INFO.ROLEMEMBERSHIPS
+          INFO.ROLES INFO.SEGMENTMAPSTORAGES INFO.SEGMENTSTORAGES
+          INFO.STORAGEFILES INFO.STORAGEFOLDERS INFO.STORAGETABLECOLUMNS
+          INFO.STORAGETABLECOLUMNSEGMENTS INFO.STORAGETABLES
+          INFO.TABLEPERMISSIONS INFO.TABLES INFO.TABLESTORAGES
+          INFO.VARIATIONS INT INTERSECT INTRATE IPMT ISAFTER ISATLEVEL ISBLANK
+          ISCROSSFILTERED ISEMPTY ISERROR ISEVEN ISFILTERED ISINSCOPE ISLOGICAL
+          ISNONTEXT ISNUMBER ISO.CEILING ISODD ISONORAFTER ISPMT
+          ISSELECTEDMEASURE ISSUBTOTAL ISTEXT KEEPFILTERS KEYWORDMATCH LAST
+          LASTDATE LASTNONBLANK LASTNONBLANKVALUE LCM LEFT LEN LINEST LINESTX LN
+          LOG LOG10 LOOKUP LOOKUPVALUE LOWER MATCHBY MAX MAXA MAXX MDURATION
+          MEDIAN MEDIANX MID MIN MINA MINUTE MINX MOD MONTH MOVINGAVERAGE MROUND
+          NAMEOF NATURALINNERJOIN NATURALLEFTOUTERJOIN NETWORKDAYS NEXT NEXTDAY
+          NEXTMONTH NEXTQUARTER NEXTYEAR NOMINAL NONVISUAL NORM.DIST NORM.INV
+          NORM.S.DIST NORM.S.INV NOT NOW NPER ODD ODDFPRICE ODDFYIELD ODDLPRICE
+          ODDLYIELD OFFSET OPENINGBALANCEMONTH OPENINGBALANCEQUARTER
+          OPENINGBALANCEYEAR OR ORDERBY PARALLELPERIOD PARTITIONBY PATH
+          PATHCONTAINS PATHITEM PATHITEMREVERSE PATHLENGTH PDURATION
+          PERCENTILE.EXC PERCENTILE.INC PERCENTILEX.EXC PERCENTILEX.INC PERMUT PI
+          PMT POISSON.DIST POWER PPMT PREVIOUS PREVIOUSDAY PREVIOUSMONTH
+          PREVIOUSQUARTER PREVIOUSYEAR PRICE PRICEDISC PRICEMAT PRODUCT
+          PRODUCTX PV QUARTER QUOTIENT RADIANS RAND RANDBETWEEN RANGE RANK
+          RANK.EQ RANKX RATE RECEIVED RELATED RELATEDTABLE REMOVEFILTERS REPLACE
+          REPT RIGHT ROLLUP ROLLUPADDISSUBTOTAL ROLLUPGROUP ROLLUPISSUBTOTAL
+          ROUND ROUNDDOWN ROUNDUP ROW ROWNUMBER RRI RUNNINGSUM SAMEPERIODLASTYEAR
+          SAMPLE SAMPLEAXISWITHLOCALMINMAX SAMPLECARTESIANPOINTSBYCOVER SEARCH
+          SECOND SELECTCOLUMNS SELECTEDMEASURE SELECTEDMEASUREFORMATSTRING
+          SELECTEDMEASURENAME SELECTEDVALUE SIGN SIN SINH SLN SQRT SQRTPI
+          STARTOFMONTH STARTOFQUARTER STARTOFYEAR STDEV.P STDEV.S STDEVX.P
+          STDEVX.S SUBSTITUTE SUBSTITUTEWITHINDEX SUM SUMMARIZE SUMMARIZECOLUMNS
+          SUMX SWITCH SYD T.DIST T.DIST.2T T.DIST.RT T.INV T.INV.2T TAN TANH
+          TBILLEQ TBILLPRICE TBILLYIELD TIME TIMEVALUE TOCSV TODAY TOJSON TOPN
+          TOPNPERLEVEL TOPNSKIP TOTALMTD TOTALQTD TOTALYTD TREATAS TRIM TRUE
+          TRUNC UNICHAR UNICODE UNION UPPER USERCULTURE USERELATIONSHIP USERNAME
+          USEROBJECTID USERPRINCIPALNAME UTCNOW UTCTODAY VALUE VALUES VAR.P VAR.S
+          VARX.P VARX.S VDB WEEKDAY WEEKNUM WINDOW XIRR XNPV YEAR YEARFRAC YIELD
+          YIELDDISC YIELDMAT
+        )
+      end
+
+      def self.statements
+        # sources:
+        # https://learn.microsoft.com/en-us/dax/
+        # https://learn.microsoft.com/en-us/dax/statements-dax
+        @statements ||= Set.new(%w(
+          AXIS ROWS COLUMN DEFINE DENSIFY EVALUATE GROUP MEASURE MPARAMETER ORDER BY 
+          RETURN START AT TABLE TOTAL VAR WITH VISUAL SHAPE IN ASC DESC SKIP DENSE
+          BLANKS FIRST LAST WEEK BOTH NONE ONEWAY ONEWAY_RIGHTFILTERSLEFT ONEWAY_LEFTFILTERSRIGHT
+          KEEP REL
+        ))
+      end
+
+      def self.data_types
+        # sources:
+        # https://dax.guide/datatypes/
+        @data_types ||= Set.new(%w(
+          BINARY BOOLEAN CURRRENCY DATETIME DECIMAL INTEGER STRING VARIANT 
+        ))
+      end
+
+      state :root do
+        rule (/\s+/m), Text::Whitespace
+        rule (/\/{2}.*/), Comment::Single
+        rule (/\/\*([\s\S]*).*\*\//m), Comment::Multiline
+        rule (/\b-?\d+(e\d+)?(\.\d+)?/), Literal::Number
+        rule (/'(?:[^']|'')*'(?!')(?:\[[ \w]+\])?|\w+\[[ \w]+\]/), Name::Entity #Tables & Column
+        rule (/\[[ \w]+\]/), Name::Entity #Measure
+        rule (/"(?:[^"]|"")*"(?!")/), Literal::String
+
+        rule %r/\w+/ do |m|
+          if self.class.functions.include? m[0].upcase
+            token Keyword
+          elsif self.class.statements.include? m[0].upcase
+            token Keyword
+          elsif self.class.data_types.include? m[0].upcase
+            token Keyword::Type
+          else
+            token Name
+          end
+        end
+
+        rule (/(?:[:\-+*\/=^><]|&{1,2}|\|{2}|\b(IN|NOT))/i), Operator
+        rule (/[;:()\[\]\{\},.]/), Punctuation
+      end
+
+    end
+  end
+end
diff --git a/spec/lexers/dax_spec.rb b/spec/lexers/dax_spec.rb
new file mode 100644
index 0000000000..a881f0f9f8
--- /dev/null
+++ b/spec/lexers/dax_spec.rb
@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+describe Rouge::Lexers::DAX do
+  let(:subject) { Rouge::Lexers::DAX.new }
+
+  describe 'guessing' do
+    include Support::Guessing
+
+    it 'guesses by filename' do
+      assert_guess :filename => 'foo.dax'
+    end
+
+  end
+
+end
diff --git a/spec/visual/samples/dax b/spec/visual/samples/dax
new file mode 100644
index 0000000000..6a4a2bf1bb
--- /dev/null
+++ b/spec/visual/samples/dax
@@ -0,0 +1,81 @@
+// Measure
+Measure1 =
+VAR currentState = SELECTEDVALUE( States [State])
+VAR currentDate = SELECTEDVALUE( 'Date'[Date] ) + 1
+VAR dataInScope =
+    CALCULATETABLE(
+        DISTINCT( data )
+        ,data[DateTime] < currentDate
+        ,REMOVEFILTERS( 'Date'[Date] )
+        ,REMOVEFILTERS( 'States'[State] )
+    )
+RETURN
+COUNTROWS(
+    CALCULATETABLE(
+        FILTER(
+            INDEX( 1, dataInScope, ORDERBY( data[DateTime], DESC), , PARTITIONBY( data[TestID] ))
+            ,[State] = currentState
+        )
+        ,REMOVEFILTERS( 'Calendar'[Date] )
+    )
+)
+
+// Query
+EVALUATE
+var OuterDateFilter = FILTER( 'Date', 'Date'[Fiscal Month] in {"FY20-May", "FY20-Jul", "FY21-Jul"} || 'Date'[Fiscal Year] in {"FY18", "FY19"} || 'Date'[Fiscal Week] in {"FY17-W01", "FY17-W02", "FY17-W03"} ) 
+var Dates = 
+    ADDCOLUMNS(
+        SUMMARIZE(
+            OuterDateFilter
+            ,'Date'[Fiscal Year]
+            ,'Date'[Fiscal Quarter]
+            ,'Date'[Fiscal Month]
+            ,'Date'[Fiscal Week]
+            ,'Date'[Date]
+        )
+        ,"@Islands" // Calcualtes the difference between the date and the row number of the table, if there is a date gap then we start a new island
+        ,DATEDIFF( 
+            RANKX ( OuterDateFilter, 'Date'[Date], , 1 )
+            ,'Date'[Date]
+            , DAY 
+        )
+    )
+var Islands =	
+	SUMMARIZE(
+		Dates
+		, [@Islands]
+		, "IslandString"
+			, var MinDate =             MIN ( 'Date'[Date] )
+			  var MaxDate =             MAX ( 'Date'[Date] )
+			  var MinFiscalYear =       CALCULATE( MIN( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Year] ))
+			  var MaxFiscalYear =       CALCULATE( MAX( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Year] ))
+			  var MinFiscalQuarter =    CALCULATE( MIN( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Quarter] ))
+			  var MaxFiscalQuarter =    CALCULATE( MAX( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Quarter] ))
+			  var MinFiscalMonth =      CALCULATE( MIN( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Month] ))
+			  var MaxFiscalMonth =      CALCULATE( MAX( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Month] ))
+			  var MinFiscalWeek =       CALCULATE( MIN( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Week] ))
+			  var MaxFiscalWeek =       CALCULATE( MAX( 'Date'[Date] ), ALLEXCEPT( 'Date', 'Date'[Fiscal Week] ))
+			  var GranularityCheck = 
+				SWITCH(
+					true
+					, MinDate = MinFiscalYear && MaxDate = MaxFiscalYear
+						, CALCULATE( MAX( 'Date'[Fiscal Year] ), 'Date'[Date] = MinDate ) & "--" & CALCULATE( MAX( 'Date'[Fiscal Year] ), 'Date'[Date] = MaxDate )
+					, MinDate = MinFiscalQuarter && MaxDate = MaxFiscalQuarter
+						, CALCULATE( MAX( 'Date'[Fiscal Quarter] ), 'Date'[Date] = MinDate ) & "--" & CALCULATE( MAX( 'Date'[Fiscal Quarter] ), 'Date'[Date] = MaxDate )
+					, MinDate = MinFiscalMonth && MaxDate = MaxFiscalMonth
+						, CALCULATE( MAX( 'Date'[Fiscal Month] ), 'Date'[Date] = MinDate ) & "--" & CALCULATE( MAX( 'Date'[Fiscal Month] ), 'Date'[Date] = MaxDate )
+					, MinDate = MinFiscalWeek && MaxDate = MaxFiscalWeek
+						, CALCULATE( MAX( 'Date'[Fiscal Week] ), 'Date'[Date] = MinDate ) & "--" & CALCULATE( MAX( 'Date'[Fiscal Week] ), 'Date'[Date] = MaxDate )
+					,MinDate & "--" & MaxDate
+				)
+			  return
+			  GranularityCheck
+	)
+var ReturnString =
+	CONCATENATEX (
+		Islands
+		, [IslandString]
+		, UNICHAR ( 10 )
+		)
+return 
+	{ReturnString}