Old:
AddDigitalSignature(X509Certificate2 certificate, string comments, DateTime signTime)
New: 
AddDigitalSignature(string certificatePath, string certificatePassword, string comments, DateTime signTime)

Document doc = new Document();
doc.LoadFromFile("sample.docx");
Document extractPage = doc.ExtractPages(0, 1);
extractPage.SaveToFile("result.docx");

TSAHttpService timestampService = new TSAHttpService("http://time2.certum.pl");

    TSAResponse response = timestampService.Check();

    //if it is success to receive tsa token
    if (response.Success)

    { formatter.TimestampService = timestampService; }

Presentation pt = new Presentation();
                    pt.loadFromFile("input.md", FileFormat.Markdown);
                    pt.saveToFile("output.pptx", FileFormat.PPTX_2013);
                    pt.dispose();

Presentation ppt = new Presentation();
            ppt.loadFromFile("input.pptx");
            for (int i = 0; i < ppt.getSlides().getCount(); i++)
            {
               ppt.getSlides().get(i).getShapes().addFromSVGAsShapes("in.svg");
            }
            ppt.saveToFile("output.pptx", FileFormat.PPTX_2013);
            ppt.dispose();

// New Append Audio
Presentation pres = new Presentation();
FileStream from_stream = File.OpenRead(inputFile);
RectangleF audioRect = new RectangleF(50, 50, 100, 100);
IAudio audio = pres.Slides[0].Shapes.AppendAudioMedia(from_stream, audioRect);
// Set the duration of the starting fade for 13s
audio.FadeInDuration = 13000f;
// Set the duration of the ending fade for 40s
audio.FadeOutDuration = 10000f;
pres.SaveToFile(outputFile, FileFormat.Pptx2013);

// Retrieve existing documents
FileStream from_stream = File.OpenRead(inputFile);
Presentation presentation = new Presentation();
presentation.LoadFromStream(from_stream, FileFormat.Auto);
foreach (IShape shape in presentation.Slides[0].Shapes)
{
    if (shape is IAudio)
    {
        IAudio audio = shape as IAudio;
        // Set the duration of the starting fade for 13s
        audio.FadeInDuration = 13000f;
        // Set the duration of the ending fade for 20s
        audio.FadeOutDuration = 20000f;
    }
}
presentation.SaveToFile(outputFile, FileFormat.Pptx2013);

// New Append Audio
Presentation pres = new Presentation();
FileStream from_stream = File.OpenRead(inputFile);
RectangleF audioRect = new RectangleF(50, 50, 100, 100);
IAudio audio = pres.Slides[0].Shapes.AppendAudioMedia(from_stream, audioRect);
// Set the start trimming time 8 seconds
audio.TrimFromStart = 8000f;
// Set the end trimming time 13 seconds
audio.TrimFromEnd = 13000f;
pres.SaveToFile(outputFile, FileFormat.Pptx2013);

// Retrieve existing documents			
FileStream from_stream = File.OpenRead(inputFile);
Presentation presentation = new Presentation();
presentation.LoadFromStream(from_stream, FileFormat.Auto);
foreach (IShape shape in presentation.Slides[0].Shapes)
{
    if (shape is IAudio)
    {
        IAudio audio = shape as IAudio;
        // Set the start trimming time 8 seconds
        audio.TrimFromStart = 8000f;
        // Set the end trimming time 13 seconds
        audio.TrimFromEnd = 13000f;
    }
}
presentation.SaveToFile(outputFile, FileFormat.Pptx2013);

IStyle style = document.Styles.FindByName("Normal");
if (style != null && style is ICharacterStyle)
{
    ICharacterStyle cStyle = style as ICharacterStyle;
    cStyle.CharacterFormat.FontName = "cambria";
    cStyle.CharacterFormat.FontSize = 14;
    cStyle.CharacterFormat.Bold = true;
    cStyle.CharacterFormat.TextColor = Color.FromArgb(42, 123, 136);
}

string pStyleName = "testStyle";
Document document = new Document();
ParagraphStyle pStyle = (ParagraphStyle)document.Styles.Add(StyleType.ParagraphStyle, pStyleName);
pStyle.CharacterFormat.FontName = "Calibri";
pStyle.CharacterFormat.FontSize = 16;
pStyle.CharacterFormat.Bold = true;
pStyle.CharacterFormat.TextColor = Color.DarkRed;
Section section = document.AddSection();
Paragraph para = section.AddParagraph();
para.ApplyStyle(pStyle);
para.AppendText("Hello world!");
Style firstParaStyle = document.FirstSection.Body.FirstParagraph.Format.Style;
document.SaveToFile(outputDocxFile1, FileFormat.Docx);
document.Styles[pStyleName].RemoveSelf();
document.SaveToFile(outputDocxFile2, FileFormat.Docx);

Document doc = new Document();
Section section = doc.AddSection();
Table table = section.AddTable();
table.ResetCells(15, 4);
for (int i = 0; i < 15; i++)
{
    TableRow row = table.Rows[i];
    for (int j = 0; j < 4; j++)
    {
        TableCell cell = row.Cells[j];
        cell.AddParagraph().AppendText(string.Format("{0} column.", (j % 2 == 0 ? "Even" : "Odd")));
        cell.AddParagraph().AppendText(string.Format("Row banding {0}", (i % 3 == 0 ? "start" : "continuation")));
    }
}

TableStyle tableStyle = (TableStyle)doc.Styles.Add(StyleType.TableStyle, "TestTableStyle1");
tableStyle.Borders.Color = Color.Black;
tableStyle.Borders.BorderType = BorderStyle.Double;

tableStyle.RowStripe = 3;
tableStyle.ConditionalStyles[TableConditionalStyleType.OddRowStripe].Shading.BackgroundPatternColor = Color.LightBlue;
tableStyle.ConditionalStyles[TableConditionalStyleType.EvenRowStripe].Shading.BackgroundPatternColor = Color.LightCyan;

tableStyle.ColumnStripe = 1;
tableStyle.ConditionalStyles[TableConditionalStyleType.EvenColumnStripe].Shading.BackgroundPatternColor = Color.LightPink;

table.ApplyStyle(tableStyle);

table.Format.StyleOptions = table.Format.StyleOptions | TableStyleOptions.ColumnStripe;

doc.SaveToFile(outputDocxFile1, FileFormat.Docx); 

Document doc = new Document();
Section section = doc.AddSection();

TableStyle tableStyle = (TableStyle)doc.Styles.Add(StyleType.TableStyle, "TestTableStyle1");
tableStyle.HorizontalAlignment = RowAlignment.Center;
tableStyle.Borders.Color = Color.Blue;
tableStyle.Borders.BorderType = BorderStyle.Single;

Table table = section.AddTable();
table.ResetCells(1, 1);
table.Rows[0].Cells[0].AddParagraph().AppendText("Aligned to the center of the page");
table.PreferredWidth = PreferredWidth.FromPoints(300);

table.ApplyStyle(tableStyle);

section.AddParagraph().AppendText(" ");

tableStyle = (TableStyle)doc.Styles.Add(StyleType.TableStyle, "TestTableStyle2");
tableStyle.LeftIndent = 55;
tableStyle.Borders.Color = Color.Green;
tableStyle.Borders.BorderType = BorderStyle.Single;

table = section.AddTable();
table.ResetCells(1, 1);
table.Rows[0].Cells[0].AddParagraph().AppendText("Aligned according to left indent");
table.PreferredWidth = PreferredWidth.FromPoints(300);

table.Format.Style = tableStyle;

doc.SaveToFile(outputDocxFile1, FileFormat.Docx); 

Document doc = new Document();
Section section = doc.AddSection();
Table table = section.AddTable();
table.ResetCells(15, 4);
for (int i = 0; i < 15; i++)
{
    TableRow row = table.Rows[i];
    for (int j = 0; j < 4; j++)
    {
        TableCell cell = row.Cells[j];
        cell.AddParagraph().AppendText(string.Format("{0} column.", (j % 2 == 0 ? "Even" : "Odd")));
        cell.AddParagraph().AppendText(string.Format("Row banding {0}", (i % 2 == 0 ? "Even" : "Odd")));
    }
}

TableStyle tableStyle = doc.AddStyle(DefaultTableStyle.LightListAccent3);
table.ApplyStyle(tableStyle);
doc.SaveToFile(outputDocxFile1, FileFormat.Docx);

Document sDoc = new Document();
sDoc.LoadFromFile(inputFile);
ToPdfParameterList toPdfParameter = new ToPdfParameterList();
toPdfParameter.DigitalSignatureInfo = new PdfDigitalSignatureInfo(pfxInputFile, pfxPassword, "Test signing", "Spire Doc"); 
toPdfParameter.DigitalSignatureInfo.HashAlgorithm = PdfDigitalSignatureHashAlgorithm.RipeMD160;
toPdfParameter.DigitalSignatureInfo.SignatureDate = nowDateTime;
toPdfParameter.DigitalSignatureInfo.TimestampConfiguration = new PdfDigitalSignatureTimestampConfiguration("https://freetsa.org/tsr", "bill", "Password");
sDoc.SaveToFile(outputFile3, toPdfParameter); 

int firstColumn = doc.Bookmarks["t_insert"].FirstColumn;
int lastColumn = doc.Bookmarks["t_insert"].LastColumn;

SearchOptions op = new SearchOptions();
op.IgnoreOfficeMath = false;
doc.Replace("ab","new", op);

Document doc = new Document("xx.docx");
ToPdfParameterList toPdf = new ToPdfParameterList(){ PageLayout = PdfPageLayout.TwoColumnLeft };
doc.SaveToFile("xx.pdf", toPdf);

Workbook workbook = new Workbook();
workbook.LoadFromFile("Equation_1.xlsx");
Worksheet sheet = workbook.Worksheets[0];
// Add a new equation at position (1, 1) with size 50x50, displaying fraction A/B
sheet.Equations.AddEquation(1, 1, 50, 50, "\\frac{A}{B}");
// Get the first equation in the worksheet
IXlsEquation equation = sheet.Equations[0];
// Update the equation content using LaTeX syntax
equation.UpdateByLatexText("\\text{tan}\\frac{\\alpha}{2}=\\frac{\\text{sin}\\alpha}{1+ \\text{cos}\\alpha}");
// Set the position and size of the equation
equation.Top = 19;
equation.Left = 72;
equation.Width = 100;
equation.Height = 100;
// Get the second equation in the worksheet
IXlsEquation equation1 = sheet.Equations[1];
// Get the collection of equation items (components of the formula)
IEquationItemCollection equationItems = equation1.EquationItems;
// Get the first item in the collection
IEquationItem item1 = equationItems[0];
item1.Text = "e-iceblue"; // Modify the text of the item
// Append a new LaTeX formula at the end
equationItems.AddByLatex("\\frac{n!}{r!(n-r)!} ");
// Insert a LaTeX formula at index 0
equationItems.InsertByLatex(0, "\\Delta A B C");
// Save the workbook
workbook.SaveToFile("out.xlsx");

HTMLOptions.Default.IsSaveFreezedPanes = true;  // true to preserve freeze panes, false to discard

sheet.Range["D7"].Formula = "=LAMBDA(val,max,IF(ISOMITTED(max),val,IF(AND(val>0,val<max),\"within range\",\"out of range\")))(A1,A2)";

sheet.Range["D5"].Formula = "=LAMBDA(a,b,IF(ISOMITTED(b),a*a,a*b))(A1,A2)";

// true: Collated printing; default false: Uncollated printing
doc.PrintSettings.Collate = true;