diff --git a/.Rbuildignore b/.Rbuildignore
index 6cd6d8c85b536ff118f5edcc0caf6668aa64fda5..74dc1230f811ac3f6125d2636233da3f97fc67b6 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -14,3 +14,5 @@
 ^inst/doc/usecase/UseCase2_PrecipitationDownscaling_RainFARM_RF4\.R$
 ^inst/doc/usecase/UseCase3_data_preparation_SCHEME_model\.R$
 ^inst/doc/usecase/launch_UseCase2_PrecipitationDownscaling_RF4\.sh$
+^.*\.Rproj$
+^\.Rproj\.user$
diff --git a/.gitignore b/.gitignore
index 2f6c062a8dacc06b63d3a1d570bf3bc74adb5cd3..89a262feca684eb5c483695ed9261014aba892af 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@ Rplots.pdf
 .nfs*
 *.RData
 !data/*.RData
+.Rproj.user
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000000000000000000000000000000000000..3faa54d96dda3af8d4e29ab8b4c8101470f6ca41
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,66 @@
+### Questions and bug reports
+
+If you have questions about the usage of a function or would like to report a bug, please follow these steps:
+
+1. Use the search function in GitLab to see if a similar problem has already been reported and/or solved.
+
+2. Rather than including a long script, try to run your code in small blocks to narrow down where the problem is coming from as much as possible.
+
+3. Open an issue tagging the maintainers (@tkariyat), and include a descriptive title and a piece of code to reproduce your problem (if applicable).
+
+### How to contribute
+
+If you would like to add a bugfix, an enhancement or a new functions, follow these steps:
+
+1. Open an issue to ask for help or describe a feature to be integrated
+
+2. Agree with the maintainers (@tkariyat) on the requirements
+
+3. Create a new branch from master with a meaningful name
+
+4. Once the development is finished, open a merge request to merge the branch on master
+
+*Note: Remember to work with multidimensional arrays with named dimensions when possible and use multiApply (https://earth.bsc.es/gitlab/ces/multiApply)*
+
+### Adding a function
+
+To add a new function in this R package, follow these considerations:
+
+* Each function exposed to the users should be in its own separate file in the R folder
+* The name of the function should match the name of the file (e.g.: `Function()` included in file **Function.R**
+* The documentation should be in roxygen2 format as a header of the function
+* Once the function and the documentation are finished, run the command `devtools::document()` in your R terminal to automatically generate the **Function.Rd** file
+* When doing the development, please use an R version between R/4.1.2 and R/4.3.x 
+
+### Style guide
+
+* Use `<-` for variable assignment
+* Include spaces between operators (e.g. `+`, `-`, `&`), before `{`, and after `for`, `if`, `while`, `,` and `)`.
+* When possible, maximum line length should be 100 characters (soft limit of 80 characters).
+* Number of indentation spaces is 2, using tabs for indentation is forbidden.
+* Double quotes are recommended for strings. When writing quotes within quoted text, use double quotes outside and single quotes inside. E.g.: `“Parameter 'na.rm' is missing.”`
+* Self-explanatory names are preferred for variables. Try to be consistent with the variable naming style. Generally: avoid special characters (except underscores) and reserved words (ex: if, for, else, …)
+* Remember to include short comments to make the code easier to understand. Comments should be in their own line and they should start with `#` followed by a space. Comments that start with `##` and a space are for details not needed to understand the general procedure but useful to make note of more technical aspects of the code.
+
+#### Examples:
+
+```r
+# Proper spacing, indentation spaces and text quotes:
+NewFunction <- function(text = "default", uppercase = TRUE) {
+  # Check uppercase parameter
+  if (!is.logical(uppercase)) {
+    stop("Parameter 'uppercase' should be TRUE or FALSE.")
+  }
+  # Only transform text if needed
+  if (uppercase && is.character(text)) {
+    text <- toupper(text)
+  }
+  return(text)
+}
+
+# How to format line breaks to avoid long lines:
+my_strings <- list(one = "one",
+                   two = "two",
+                   three = "three",
+                   four = "four")
+```
diff --git a/cstools b/cstools
new file mode 160000
index 0000000000000000000000000000000000000000..fc486262cbf4b7bd70314fd5fec7405cd9089fd9
--- /dev/null
+++ b/cstools
@@ -0,0 +1 @@
+Subproject commit fc486262cbf4b7bd70314fd5fec7405cd9089fd9
diff --git a/cstools.Rproj b/cstools.Rproj
new file mode 100644
index 0000000000000000000000000000000000000000..21a4da087e1c026c953a49de88caea1247cd1f1b
--- /dev/null
+++ b/cstools.Rproj
@@ -0,0 +1,17 @@
+Version: 1.0
+
+RestoreWorkspace: Default
+SaveWorkspace: Default
+AlwaysSaveHistory: Default
+
+EnableCodeIndexing: Yes
+UseSpacesForTab: Yes
+NumSpacesForTab: 2
+Encoding: UTF-8
+
+RnwWeave: Sweave
+LaTeX: pdfLaTeX
+
+BuildType: Package
+PackageUseDevtools: Yes
+PackageInstallArgs: --no-multiarch --with-keep.source