diff --git a/compiler/dub.json b/compiler/dub.json
index 8172f18..8e5c6ab 100644
--- a/compiler/dub.json
+++ b/compiler/dub.json
@@ -5,5 +5,8 @@
 	"copyright": "Copyright © 2023, Andrew Lalis",
 	"description": "Compiler for the NIMP language.",
 	"license": "MIT",
-	"name": "compiler"
+	"name": "compiler",
+	"dependencies": {
+		"streams": "~>3.4.3"
+	}
 }
\ No newline at end of file
diff --git a/compiler/dub.selections.json b/compiler/dub.selections.json
new file mode 100644
index 0000000..163bdbb
--- /dev/null
+++ b/compiler/dub.selections.json
@@ -0,0 +1,6 @@
+{
+	"fileVersion": 1,
+	"versions": {
+		"streams": "3.4.3"
+	}
+}
diff --git a/compiler/source/app.d b/compiler/source/app.d
index b02f56e..9256711 100644
--- a/compiler/source/app.d
+++ b/compiler/source/app.d
@@ -1,5 +1,18 @@
 import std.stdio;
+import std.string;
+import nimpc;
+import streams;
 
-void main() {
-	writeln("Edit source/app.d to start your project.");
+int main(string[] args) {
+	if (args.length < 2) {
+		writeln("Missing required file args.");
+		return 1;
+	}
+	string[] files = args[1 .. $];
+	writefln!"Compiling %s"(files);
+	foreach (filename; files) {
+		auto sIn = FileInputStream(toStringz(filename));
+		auto tokens = tokenize(sIn);
+	}
+	return 0;
 }
diff --git a/compiler/source/nimpc/ast/package.d b/compiler/source/nimpc/ast/package.d
new file mode 100644
index 0000000..338fb9c
--- /dev/null
+++ b/compiler/source/nimpc/ast/package.d
@@ -0,0 +1,6 @@
+/**
+ * This module contains definitions for the components in NIMP's abstract
+ * syntax tree.
+ */
+module nimpc.ast;
+
diff --git a/compiler/source/nimpc/lexer.d b/compiler/source/nimpc/lexer.d
new file mode 100644
index 0000000..18f279a
--- /dev/null
+++ b/compiler/source/nimpc/lexer.d
@@ -0,0 +1,62 @@
+module nimpc.lexer;
+
+import streams;
+import std.stdio;
+import std.regex;
+import std.array;
+
+enum TokenType {
+    KEYWORD,
+    DATA_TYPE,
+    SENTENCE_END,
+    LITERAL_INTEGER,
+    LITERAL_FLOAT,
+    LITERAL_BOOLEAN,
+    LITERAL_STRING
+}
+
+struct Token {
+    TokenType type;
+    string content;
+    uint line;
+    uint column;
+}
+
+class LexerException : Exception {
+    const uint sourceLine;
+    const uint sourceColumn;
+
+    this(string msg, uint sourceLine, uint sourceColumn) {
+        super(msg);
+        this.sourceLine = sourceLine;
+        this.sourceColumn = sourceColumn;
+    }
+}
+
+/**
+ * Parses a list of tokens from an input stream of lines of code.
+ * Params:
+ *   inputStream = The lines of input to parse.
+ * Returns: A list of tokens.
+ */
+Token[] tokenize(S)(S inputStream) if (isInputStream!(S, char)) {
+    Appender!(Token[]) tokenApp;
+    uint line = 0;
+    uint col = 0;
+
+    while (true) {
+        char c = readChar(inputStream, line, col);
+        writeln(c);
+    }
+
+
+    return tokenApp[];
+}
+
+private char readChar(S)(S stream, uint line, uint col) if (isInputStream!(S, char)) {
+    auto result = readOne(stream);
+    if (result.hasError) {
+        throw new LexerException("Failed to read one more char from stream.", line, col);
+    }
+    return result.element;
+}
diff --git a/compiler/source/nimpc/package.d b/compiler/source/nimpc/package.d
new file mode 100644
index 0000000..95b7a58
--- /dev/null
+++ b/compiler/source/nimpc/package.d
@@ -0,0 +1,8 @@
+/**
+ * The NIMP compiler front-end module, which includes the language's lexer,
+ * parser, and syntax tree.
+ */
+module nimpc;
+
+public import nimpc.ast;
+public import nimpc.lexer;