diff --git a/Cargo.toml b/Cargo.toml
index 33eaa4f..936839e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,15 +1,15 @@
 [package]
 name = "rusty-fib-facts"
-version = "0.1.0"
+version = "0.2.0"
 authors = ["Timothy J Warren <tim@timshomepage.net>"]
-edition = "2018"
+edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 
 [dev-dependencies]
-criterion = "0.3"
+criterion = { version="0.3.5", features=["html_reports"] }
 
 [[bench]]
 name = "stock_functions"
diff --git a/src/lib.rs b/src/lib.rs
index 3a94681..a799a39 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,21 +1,12 @@
 //! # Rusty Fib Facts
 //!
-//! Implementations of common math algorithms to benchmark
+//! Implementations of common algorithms to benchmark
 #![forbid(unsafe_code)]
-#![no_std]
 
-use core::cmp::{max, min};
+pub mod parallel;
 
-#[cfg(all(feature = "alloc", not(feature = "std")))]
-#[macro_use]
-extern crate alloc;
-
-#[cfg(feature = "std")]
-#[macro_use]
-extern crate std;
-
-#[cfg(feature = "std")]
-use core::f64::consts::{E, PI};
+use std::cmp::{max, min};
+use std::f64::consts::{E, PI};
 
 /// Calculate a number in the fibonacci sequence,
 /// using recursion and a lookup table
@@ -150,7 +141,7 @@ pub fn it_factorial(n: usize) -> Option<u128> {
     }
 }
 
-/// Calculate the value of a factorial recrursively
+/// Calculate the value of a factorial recursively
 ///
 /// Can calculate up to 34! using native unsigned 128 bit integers.
 ///
@@ -191,7 +182,6 @@ pub fn factorial(n: usize) -> Option<u128> {
 /// let invalid = approx_factorial(171.0); // None
 /// # assert!(invalid.is_none());
 /// ```
-#[cfg(feature = "std")]
 #[inline]
 pub fn approx_factorial(n: f64) -> Option<f64> {
     let power = (n / E).powf(n);
@@ -199,7 +189,7 @@ pub fn approx_factorial(n: f64) -> Option<f64> {
 
     let res = power * root;
 
-    if res >= core::f64::MIN && res <= core::f64::MAX {
+    if res >= std::f64::MIN && res <= std::f64::MAX {
         Some(res)
     } else {
         None
@@ -335,7 +325,6 @@ mod tests {
         assert!(it_factorial(35).is_none());
     }
 
-    #[cfg(feature = "std")]
     #[test]
     fn test_approx_factorial() {
         assert!(approx_factorial(170.624).is_some());