As we turn to Page 5, we got off to a better start than we expected.
In addition, we continue to see accelerating software recurring revenue growth, growing approximately 6% on an organic basis.
The growth in cash flow performance in the quarter allowed us to continue our rapid deleveraging with about $500 million in debt pay-down during the quarter.
Turning to Page 6 and covering the Q1 financial highlights.
Total revenue increased 13% to $1.53 billion, which was an all-time record for any Roper quarter.
Organic revenue for the enterprise declined 1% versus last year's plus 4% pre-pandemic comp.
EBITDA grew 20% to $561 million.
EBITDA margin increased 220 basis points to 36.7%, on really great incrementals across the portfolio.
Adjusted DEPS was $3.60, 18% above prior year.
Free cash flow was $543 million, up 54%.
Our results were enhanced a bit by approximately $40 million of accelerated payments that were the result of wins at our UK-based CliniSys laboratory software business.
Aided by our outstanding cash flow performance, we reduced our debt by approximately $500 million in the quarter.
Turning to Page 7, an update on our deleveraging.
In the first quarter, we reduced our debt by approximately $500 million.
Over the first three months of the year, our EBITDA growth, combined with debt reduction, enabled us to lower our net debt to EBITDA ratio from 4.7 to 4.2.
As we turn to Page 9, revenues in our Application Software segment were $578 million, up 2% on organic basis.
EBITDA margins were an impressive 44.9% in the quarter.
Across this segment, we saw organic recurring revenue, which is about 75% of the revenue for this segment, increase approximately 6%.
CliniSys has approximately 85% market share in the UK and is now recognized as one of four critical IT vendors for the entire National Health Service.
Turning to Page 10.
Revenue in our network segment were $440 million, flat versus last year and down 3% on an organic basis.
EBITDA margins were 40.9% in the quarter.
Our software businesses in this segment, about 65% of the revenues were up 4% on an organic basis.
This revenue was broad based among our software businesses and driven by organic recurring revenue growth of approximately 6%.
Our non-software businesses in this segment were down 13% for the quarter; a touch better than we anticipated.
As we turn to Page 11, revenues in our MAS segment were $381 million, up 2% on an organic basis.
EBITDA margins were 34.8% in the quarter.
As we turn to Page 12, revenues in our Process Technology segment were $131 million, down 10% on an organic basis, EBITDA margins hung in at 31% in the quarter.
Now, please turn to Page 14, where I'll highlight our increased guidance for 2021.
Based on strong Q1 performance and our increased confidence for the balance of the year, we're raising our full-year adjusted DEPS to be in the range of $14.75 and $15 per share and organic growth to be in the 6% to 7% range.
The 6% to 7% organic growth is against a 1% organic decline in 2020.
Our tax rate should continue to be in the 21% to 22% range.
For the second quarter, we're establishing adjusted DEPS guidance to be between $3.61 and $3.65 and expect second quarter organic revenue growth to be in line with the full-year organic growth rate.
Turning to Page 15 and our closing summary.
EBITDA margins expanded nicely and free cash flow grew 54% to $543 million, which enabled us to continue our rapid deleveraging in the quarter.
Bill has been a Roper Director since 1997 and has reached our mandatory Board retirement age.

Summary:
Total revenue increased 13% to $1.53 billion, which was an all-time record for any Roper quarter.
Adjusted DEPS was $3.60, 18% above prior year.
Based on strong Q1 performance and our increased confidence for the balance of the year, we're raising our full-year adjusted DEPS to be in the range of $14.75 and $15 per share and organic growth to be in the 6% to 7% range.
For the second quarter, we're establishing adjusted DEPS guidance to be between $3.61 and $3.65 and expect second quarter organic revenue growth to be in line with the full-year organic growth rate.