PM> Install-Package Spire.XLS

using Spire.Xls;

namespace ConvertXlsToXlsx
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Workbook instance
            Workbook workbook = new Workbook();
            //Load an XLS file
            workbook.LoadFromFile("Input.xls");

            //Convert the file to XLSX format
            workbook.SaveToFile("ToXlsx.xlsx", ExcelVersion.Version2016);
        }
    }
}

Imports Spire.Xls

Namespace ConvertXlsToXlsx
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Workbook instance
            Dim workbook As Workbook = New Workbook()
            'Load an XLS file
            workbook.LoadFromFile("Input.xls")

            'Convert the file to XLSX format
            workbook.SaveToFile("ToXlsx.xlsx", ExcelVersion.Version2016)
        End Sub
    End Class
End Namespace

using Spire.Xls;

namespace ConvertXlsxToXls
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Workbook instance
            Workbook workbook = new Workbook();
            //Load an XLSX file
            workbook.LoadFromFile("Input.xlsx");

            //Convert the file to XLS format
            workbook.SaveToFile("ToXls.xls", ExcelVersion.Version97to2003);
        }
    }
}

Imports Spire.Xls

Namespace ConvertXlsxToXls
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Workbook instance
            Dim workbook As Workbook = New Workbook()
            'Load an XLSX file
            workbook.LoadFromFile("Input.xlsx")

            'Convert the file to XLS format
            workbook.SaveToFile("ToXls.xls", ExcelVersion.Version97to2003)
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.PDF

using Spire.Pdf;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace DeleteBlankPage
{
    class Program
    {
        static void Main(string[] args)
        {
            //Apply license by license key
            Spire.License.LicenseProvider.SetLicenseKey("your license key");

            //Create a PdfDocument instance
            PdfDocument document = new PdfDocument();

            //Load a sample PDF document
            document.LoadFromFile("input.pdf");

            //Loop through all pages in the PDF
            for (int i = document.Pages.Count - 1; i >= 0; i--)
            {
                //Detect if a page is blank
                if (document.Pages[i].IsBlank())
                {
                    //Remove the absolutely blank page
                    document.Pages.RemoveAt(i);
                }
                else
                {
                    //Save PDF page as image
                    Image image = document.SaveAsImage(i, PdfImageType.Bitmap);

                    //Detect if the converted image is blank
                    if (IsImageBlank(image))
                    {
                        //Remove the page
                        document.Pages.RemoveAt(i);
                    }
                }
            }

            //Save the result document
            document.SaveToFile("RemoveBlankPage.pdf", FileFormat.PDF);
        }

        //Detect if an image is blank
        public static bool IsImageBlank(Image image)
        {
            Bitmap bitmap = new Bitmap(image);
            for (int i = 0; i < bitmap.Width; i++)
            {
                for (int j = 0; j < bitmap.Height; j++)
                {
                    Color pixel = bitmap.GetPixel(i, j);
                    if (pixel.R < 240 || pixel.G < 240 || pixel.B < 240)
                    {
                        return false;
                    }
                }
            }
            return true;
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Graphics

Namespace DeleteBlankPage
    Class Program
        Private Shared Sub Main(ByVal args() As String)
            'Apply license by license key
            Spire.License.LicenseProvider.SetLicenseKey("your license key")

            'Create a PdfDocument instance
            Dim document As PdfDocument = New PdfDocument

            'Load a sample PDF document
            document.LoadFromFile("input.pdf")

            'Loop through all pages in the PDF
            Dim i As Integer = (document.Pages.Count - 1)
            Do While (i >= 0)

                'Detect if a page is blank
                If document.Pages(i).IsBlank Then

                    'Remove the absolutely blank page
                    document.Pages.RemoveAt(i)
                Else

                    'Save PDF page as image
                    Dim image As Image = document.SaveAsImage(i, PdfImageType.Bitmap)

                    'Detect if the converted image is blank
                    If Program.IsImageBlank(image) Then

                        'Remove the page
                        document.Pages.RemoveAt(i)
                    End If

                End If

                i = (i - 1)
            Loop

            'Save the result document
            document.SaveToFile("RemoveBlankPage.pdf", FileFormat.PDF)
        End Sub

        'Detect if an image is blank
        Public Shared Function IsImageBlank(ByVal image As Image) As Boolean
            Dim bitmap As Bitmap = New Bitmap(image)
            Dim i As Integer = 0
            Do While (i < bitmap.Width)
                Dim j As Integer = 0
                Do While (j < bitmap.Height)
                    Dim pixel As Color = bitmap.GetPixel(i, j)
                    If ((pixel.R < 240) _
                                OrElse ((pixel.G < 240) _
                                OrElse (pixel.B < 240))) Then
                        Return False
                    End If

                    j = (j + 1)
                Loop

                i = (i + 1)
            Loop

            Return True
        End Function
    End Class
End Namespace

PM> Install-Package Spire.Presentation

using Spire.Presentation;
using Spire.Presentation.Collections;
using System.Drawing;

namespace ExtractImagesFromPresentation
{
    internal class Program
    {
        static void Main(string[] args)
        {
            //Initialize an instance of the Presentation class
            Presentation ppt = new Presentation();
            //Load a PowerPoint presentation
            ppt.LoadFromFile(@"Template.pptx");

            //Get the image collection of the presentation
            ImageCollection imageCollection = ppt.Images;

            //Iterate through the images in the collection
            for (int i = 0; i < imageCollection.Count; i++)
            {
                //Extract the images 
                imageCollection[i].Image.Save(string.Format(@"Presentation\Images{0}.png", i));
            }

            ppt.Dispose();
        }
    }
}

Imports Spire.Presentation
Imports Spire.Presentation.Collections

Namespace ExtractImagesFromPresentation
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Initialize an instance of the Presentation class
            Dim ppt As Presentation = New Presentation()
            'Load a PowerPoint presentation
            ppt.LoadFromFile("Template.pptx")

            'Get the image collection of the presentation
            Dim imageCollection As ImageCollection = ppt.Images

            'Iterate through the images in the collection
            For i As Integer = 0 To imageCollection.Count - 1
                'Extract the images 
                imageCollection(i).Image.Save(String.Format("Presentation\Images{0}.png", i))
            Next

            ppt.Dispose()
        End Sub
    End Class
End Namespace

using Spire.Presentation;

namespace ExtractImagesFromSlide
{
    internal class Program
    {
        static void Main(string[] args)
        {
            //Initialize an instance of the Presentation class
            Presentation ppt = new Presentation();
            //Load a PowerPoint presentation
            ppt.LoadFromFile(@"Template4.pptx");

            //Get the first slide
            ISlide slide = ppt.Slides[0];

            int i = 0;
            //Iterate through all shapes on the first slide
            foreach (IShape s in slide.Shapes)
            {
                //Check if the shape is of SlidePicture type
                if (s is SlidePicture)
                {
                    //Extract the image
                    SlidePicture ps = s as SlidePicture;
                    ps.PictureFill.Picture.EmbedImage.Image.Save(string.Format(@"Slide\Images{0}.png", i));
                    i++;
                }
                //Check if the shape is of PictureShape type
                if (s is PictureShape)
                {
                    //Extract the image
                    PictureShape ps = s as PictureShape;
                    ps.EmbedImage.Image.Save(string.Format(@"Slide\Images{0}.png", i));
                    i++;
                }
            }
        }
    }
}

Imports Spire.Presentation

Namespace ExtractImagesFromSlide
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Initialize an instance of the Presentation class
            Dim ppt As Presentation = New Presentation()
            'Load a PowerPoint presentation
            ppt.LoadFromFile("Template4.pptx")

            'Get the first slide
            Dim slide As ISlide = ppt.Slides(0)

            Dim i = 0
            'Iterate through all shapes on the first slide
            For Each s As IShape In slide.Shapes
                'Check if the shape is of SlidePicture type
                If TypeOf s Is SlidePicture Then
                    'Extract the image
                    Dim ps As SlidePicture = TryCast(s, SlidePicture)
                    ps.PictureFill.Picture.EmbedImage.Image.Save(String.Format("Slide\Images{0}.png", i))
                    i += 1
                End If
                'Check if the shape is of PictureShape type
                If TypeOf s Is PictureShape Then
                    'Extract the image
                    Dim ps As PictureShape = TryCast(s, PictureShape)
                    ps.EmbedImage.Image.Save(String.Format("Slide\Images{0}.png", i))
                    i += 1
                End If
            Next
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.Doc

using Spire.Doc;
using Spire.Doc.Documents;
using Spire.Doc.Fields;

namespace InsertSuperscriptAndSubscript
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Document instance
            Document document = new Document();
            //Load a Word document
            document.LoadFromFile("Sample.docx");

            //Get the first section
            Section section = document.Sections[0];

            //Add a paragraph to the section
            Paragraph paragraph = section.AddParagraph();

            //Add normal text to the paragraph
            paragraph.AppendText("E = mc");
            //Add superscript text to the paragraph
            TextRange superscriptText = paragraph.AppendText("2");
            //Apply superscript formatting to the superscript text
            superscriptText.CharacterFormat.SubSuperScript = SubSuperScript.SuperScript;

            //Start a new line
            paragraph.AppendBreak(BreakType.LineBreak);

            //Add normal text to the paragraph
            paragraph.AppendText("H");
            //Add subscript text to the paragraph
            TextRange subscriptText = paragraph.AppendText("2");
            //Apply subscript formatting to the subscript text
            subscriptText.CharacterFormat.SubSuperScript = SubSuperScript.SubScript;
            //Add normal text to the paragraph
            paragraph.AppendText("O");

            //Set font size for the text in the paragraph
            foreach (var item in paragraph.Items)
            {
                if (item is TextRange)
                {
                    TextRange textRange = item as TextRange;
                    textRange.CharacterFormat.FontSize = 36f;
                }
            }

            //Save the result document
            document.SaveToFile("InsertSuperscriptAndSubscript.docx", FileFormat.Docx2013);
        }
    }
}

Imports Spire.Doc
Imports Spire.Doc.Documents
Imports Spire.Doc.Fields

Namespace InsertSuperscriptAndSubscript
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Document instance
            Dim document As Document = New Document()
            'Load a Word document
            document.LoadFromFile("Sample.docx")

            'Get the first section
            Dim section As Section = document.Sections(0)

            'Add a paragraph to the section
            Dim paragraph As Paragraph = section.AddParagraph()

            'Add normal text to the paragraph
            paragraph.AppendText("E = mc")
            'Add superscript text to the paragraph
            Dim superscriptText As TextRange = paragraph.AppendText("2")
            'Apply superscript formatting to the superscript text
            superscriptText.CharacterFormat.SubSuperScript = SubSuperScript.SuperScript

            'Start a new line
            paragraph.AppendBreak(BreakType.LineBreak)

            'Add normal text to the paragraph
            paragraph.AppendText("H")
            'Add subscript text to the paragraph
            Dim subscriptText As TextRange = paragraph.AppendText("2")
            'Apply subscript formatting to the subscript text
            subscriptText.CharacterFormat.SubSuperScript = SubSuperScript.SubScript
            'Add normal text to the paragraph
            paragraph.AppendText("O")

            'Set font size for the text in the paragraph
            For Each item In paragraph.Items
                If TypeOf item Is TextRange Then
                    Dim textRange As TextRange = TryCast(item, TextRange)
                    textRange.CharacterFormat.FontSize = 36F
                End If
            Next

            'Save the result document
            document.SaveToFile("InsertSuperscriptAndSubscript.docx", FileFormat.Docx2013)
        End Sub
    End Class
End Namespace